static void Main(string[] args)
{
"Testing Scheduler Package".title('=');
Console.WriteLine();
DBEngine <int, DBElement <int, ListOfStrings> > dbEngineType1 = new DBEngine <int, DBElement <int, ListOfStrings> >();
DBElement <int, ListOfStrings> elem = new DBElement <int, ListOfStrings>();
"Testing function makeDataForDB() by creating metadata for Type1 = <string,ListOfStrings> and Type2 = <int,string>".title('-');
elem.name = "X";
elem.descr = "description";
elem.timeStamp = DateTime.Now;
elem.payload = new ListOfStrings();
elem.payload.theWrappedData = new List <string> {
"payload1", "payload2"
};
dbEngineType1.insert(1, elem);
"Scheduler is persisting data every one second. Press any key to exit".title('-');
Scheduler schd = new Scheduler(1000, dbEngineType1);
schd.schedular.Enabled = true;
Console.ReadKey();
Console.Write("\n\n");
}
void TestR5()
{
"Demonstrating Requirement #5".title();
DBElement <int, string> elem2 = new DBElement <int, string>();
elem2.name = "element#2";//add a new key/value pairs
elem2.descr = "test element#2";
elem2.timeStamp = DateTime.Now;
elem2.children.AddRange(new List <int> {
16, 48
});
elem2.payload = "elem#2's payload";
//elem2.showElement();
db.insert(7, elem2);
PersistToXML toxml = new PersistToXML(db);
toxml.writeXML();
Write("\n --- Test read XML file Start---");
LoadXML fromxml = new LoadXML(db, @"C:\Users\lxinghe\Downloads\Project2Starter\ReadFile.xml");
fromxml.WriteToDBEngine();
Write("\n\n Show key/value pairs in data base:\n");
db.showDB();
Write("\n --- Test read XML file End---");
WriteLine();
}
void TestR6()
{
int interval = 100;
"Demonstrating Requirement #6".title();
WriteLine("\n Enabled Scheduler for {0} miliseconds", interval);
Scheduler schedular = new Scheduler(interval, db1);
schedular.schedular.Enabled = true;
WriteLine();
for (int i = 10; i < 20; i++)
{
DBElement <int, ListOfStrings> newelement = new DBElement <int, ListOfStrings>();
newelement.name = "newelement int-ListOfString : " + i.ToString();
newelement.descr = "Scheduler requirement demonstration : " + i.ToString();
newelement.timeStamp = DateTime.Now;
newelement.children.AddRange(new List <int> {
1 + i, 2 + i, 3 + i, 4 + i, 5 + i
});
newelement.payload = new ListOfStrings();
newelement.payload.theWrappedData = new List <string> {
"CSE6814" + i.ToString(), "SMA4" + i.ToString(), "C#.net4" + i.ToString(), "AI4" + i.ToString()
};
if (db1.insert(i, newelement))
{
WriteLine(" Added in in-memory database.");
}
else
{
WriteLine(" Insert failed into in-memory database.");
}
}
WriteLine();
WriteLine(" Adding new elements in in-memory database and it will be persist to xml file automatically.");
}
//----< write metadata to string >--------------------------------
public static string showMetaData <Key, Data>(this DBElement <Key, Data> elem)
{
StringBuilder accum = new StringBuilder();
accum.Append(String.Format("\n name: {0}", elem.name));
accum.Append(String.Format("\n desc: {0}", elem.descr));
accum.Append(String.Format("\n desc: {0}", elem.timeStamp));
if (elem.children.Count() > 0)
{
accum.Append(String.Format("\n Children: "));
bool first = true;
foreach (Key key in elem.children)
{
if (first)
{
accum.Append(String.Format("{0}", key.ToString()));
first = false;
}
else
{
accum.Append(String.Format(", {0}", key.ToString()));
}
}
}
return(accum.ToString());
}
void TestR3()//addition and deletion of key/value pairs
{
"Demonstrating Requirement #3".title();
WriteLine();
Write("\n --- Test addition of key/value pairs Start---");
WriteLine();
DBElement <int, string> elem1 = new DBElement <int, string>();
elem1.name = "element#1";//add a new key/value pairs
elem1.descr = "test element#1";
elem1.timeStamp = DateTime.Now;
elem1.children.AddRange(new List <int> {
6, 8
});
elem1.payload = "elem#1's payload";
elem1.showElement();
db.insert(2, elem1);
Write("\n\n Show key/value pairs in data base:\n");
db.showDB();
WriteLine();
Write("\n --- Test addition of key/value pairs End---");
WriteLine();
Write("\n --- Test deletion of key/value pairs Start---");
WriteLine();
db.delete(1);//delete an existing key/value pairs
Write("\n\n Show key/value pairs in data base:\n");
db.showDB();
WriteLine();
db.delete(100);//try to delete a key/value pairs that doesn't exist
Write("\n --- Test deletion of key/value pairs End---");
WriteLine();
}
static void Main(string[] args)
{
"Testing ItemEditor Package".title('=');
Console.WriteLine();
DBEngine <int, DBElement <int, ListOfStrings> > db1 = new DBEngine <int, DBElement <int, ListOfStrings> >();
ItemEditor <int, string> itemEditor = new ItemEditor <int, string>();
"For key = 1, metadata before editing is: ".title('-');
DBElement <int, ListOfStrings> elem1 = new DBElement <int, ListOfStrings>();
elem1.name = "1st Key/Value = Int/ListOfStrings";
elem1.descr = "This is first element of Int/ListOfStrings key value pair.";
elem1.timeStamp = DateTime.Now;
elem1.children.AddRange(new List <int> {
100, 101, 102, 103, 104, 105
});
elem1.payload = new ListOfStrings();
elem1.payload.theWrappedData = new List <string> {
"CSE681", "SMA", "C#.net", "AI"
};
db1.insert(1, elem1);
db1.showDB();
Console.WriteLine("\n\n");
"For key = 1, metadata after editing is: ".title('-');
itemEditor.editByName(ref db1, 1, "NewX");
itemEditor.editByDescr(ref db1, 1, "NewDescription");
db1.showDB();
Console.WriteLine("\n\n");
}
public Func <Key, bool> defineTimeStampQuery(DateTime startTime, DateTime?endTime = null)
{
Func <Key, bool> queryPredicate = (Key key) =>
{
if (!db.Keys().Contains(key))
{
return(false);
}
else
{
if (endTime == null)
{
endTime = DateTime.Now;
}
DBElement <Key, Value> value;
db.getValue(key, out value);
DBElement <Key, Value> elem = value as DBElement <Key, Value>;
int cond1 = DateTime.Compare(elem.timeStamp, startTime);
int cond2 = DateTime.Compare(elem.timeStamp, (DateTime)endTime);
if (cond1 >= 0 && cond2 <= 0)
{
return(true);
}
}
return(false);
};
return(queryPredicate);
}
static void Main(string[] args)
{
"Testing DBExtensions Package".title('=');
WriteLine();
Write("\n --- Test DBElement<int,string> ---");
DBElement <int, string> elem1 = new DBElement <int, string>();
elem1.payload = "a payload";
Write(elem1.showElementWithTestType1 <int>());
WriteLine();
Write("\n --- Test DBElement<string,List<string>> ---");
DBElement <string, List <string> > newelem1 = new DBElement <string, List <string> >();
newelem1.name = "newelem1";
newelem1.descr = "test new type";
newelem1.children = new List <string> {
"Key1", "Key2"
};
newelem1.payload = new List <string> {
"one", "two", "three"
};
Write(newelem1.showElementWithTestType2 <string>());
WriteLine();
Write("\n\n");
}
public void dateTimeSearch(DateTime fromDate, DateTime toDate, DBEngine <string, DBElement <string, List <string> > > db)
{
if (toDate == default(DateTime))
{
toDate = DateTime.Now;
}
Console.WriteLine("\nSearching key within timeStamp between '{0}' and '{1}'", fromDate, toDate);
List <string> foundKeys = new List <string>();
IEnumerable <string> keys = db.Keys();
foreach (string key in keys)
{
DBElement <string, List <string> > elem = new DBElement <string, List <string> >();
db.getValue(key, out elem);
if (elem.timeStamp <= toDate && elem.timeStamp > fromDate)
{
foundKeys.Add(key);
}
}
foreach (string key1 in foundKeys)
{
Console.WriteLine("dateTime Key={0}", key1);
}
}
//----< write details of an Enumerable element to string >--------
public static string showEnumerableElement <Key, Data, T>(this DBElement <Key, Data> elem)
where Data : IEnumerable <T> // constraint clause
{
StringBuilder accum = new StringBuilder();
accum.Append(elem.showMetaData());
if (elem.payload != null)
{
bool first = true;
accum.Append(String.Format("\n payload:\n "));
foreach (var item in elem.payload) // won't compile without constraint clause
{
if (first)
{
accum.Append(String.Format("{0}", item));
first = false;
}
else
{
accum.Append(String.Format(", {0}", item));
}
}
}
return(accum.ToString());
}
public void metaDataPattern(string pattern, DBEngine <string, DBElement <string, List <string> > > db)
{
Console.WriteLine("\nSearching key with a pattern='{0}' in the metadata", pattern);
List <string> foundKeys = new List <string>();
IEnumerable <string> keys = db.Keys();
foreach (string key in keys)
{
DBElement <string, List <string> > elem = new DBElement <string, List <string> >();
db.getValue(key, out elem);
if (elem.name.Contains(pattern))
{
foundKeys.Add(key);
}
else if (elem.descr.Contains(pattern))
{
foundKeys.Add(key);
}
else if (elem.timeStamp.ToString().Contains(pattern))
{
foundKeys.Add(key);
}
}
foreach (string key1 in foundKeys)
{
Console.WriteLine("Found Key={0}", key1);
}
}
static void Main(string[] args)
{
"Testing persist engine package".title();
DBEngine<string, DBElement<string, List<string>>> dbString = new DBEngine<string, DBElement<string, List<string>>>();
DBElement<string, List<String>> elemString = new DBElement<string, List<String>>();
elemString.name = "Element2";
elemString.descr = "testelement2";
elemString.timeStamp = DateTime.Now;
elemString.children.AddRange(new List<string> { "SMA1", "Syracuse2", "NY3" });
elemString.payload = new List<string>();
elemString.payload.AddRange(new List<string> { "we", "rock", "the ", "world" });
//elem.showElement();
dbString.insert("Prohject2", elemString);
DBElement<string, List<String>> elemString2 = new DBElement<string, List<String>>();
elemString2.name = "Element3";
elemString2.descr = "test element3";
elemString2.timeStamp = DateTime.Now;
elemString2.children.AddRange(new List<string> { "SMA2", "Syracuse22", "NY33" });
elemString2.payload = new List<string>();
elemString2.payload.AddRange(new List<string> { "Thug", "Life" });
//elem.showElement();
dbString.insert("Thug3", elemString2);
PersistEngine<string> test = new PersistEngine<string>();
test.createXML(dbString);
}
static void Main(string[] args)
{
DBEngine <int, DBElement <int, string> > db = new DBEngine <int, DBElement <int, string> >();
DBElement <int, string> elem = new DBElement <int, string>(); //Populating DBEngine
elem.name = "Element2"; //object db
elem.descr = "test element2"; //for testing data int and string type.
elem.timeStamp = DateTime.Now;
elem.children.AddRange(new List <int> {
});
elem.payload = "Varun";
db.insert(1, elem);
DBElement <int, string> elem1 = new DBElement <int, string>(); //Populating DBEngine
elem1.name = "Key/Value pair to be edited"; //object db
elem1.descr = "test element3"; //for testing data int and string type.
elem1.timeStamp = DateTime.Now;
elem1.children.AddRange(new List <int> {
4, 5, 6
});
elem1.payload = "EDIT !";
db.insert(2, elem1);
DBFactory <int, DBElement <int, string> > dff = new DBFactory <int, DBElement <int, string> >(db);
dff.getValue(1, out elem1);
Console.WriteLine(elem1.name);
}
void TestR8()
{
"Demonstrating Requirement #8".title();
DBFactory <string, DBElement <string, List <string> > > dbFac; // immutable db object
DBEngine <string, DBElement <string, List <string> > > dbImmut = new DBEngine <string, DBElement <string, List <string> > >();
List <string> fetchedKeys = new List <string>();
fetchedKeys = QE1.keyPattern(".*hu.*", dbString);
foreach (string key in fetchedKeys)
{
DBElement <string, List <String> > elem = new DBElement <string, List <String> >();
dbString.getValue(key, out elem);
dbImmut.insert(key, elem);
}
//dbImmut.showEnumerableDB();
dbFac = new DBFactory <string, DBElement <string, List <string> > >(dbImmut); // populating immutable db
WriteLine("\nDisplaying the contents of the immutable database");
dbFac.showEnumerableDB();
WriteLine();
}
void TestR4()
{
WriteLine();
"Demonstrating Requirement #4".title();
DBElement <int, string> elem = new DBElement <int, string>(); //Populating DBEngine
elem.name = "Element2"; //object db
elem.descr = "test element2"; //for testing data int and string type.
elem.timeStamp = DateTime.Now;
elem.children.AddRange(new List <int> {
});
elem.payload = "Varun";
db.insert(1, elem);
DBElement <int, List <string> > elemPayload2 = new DBElement <int, List <string> >(); //Populating DBEngine
elemPayload2.name = "Element5"; //object dbPay
elemPayload2.descr = "test element5"; //for testing data int and list of string type.
elemPayload2.timeStamp = DateTime.Now;
elemPayload2.children.AddRange(new List <int> {
98, 22, 35
});
elemPayload2.payload = new List <string>();
elemPayload2.payload.AddRange(new List <string> {
"we", "rock", "the", "world"
});
dbPay.insert(2, elemPayload2);
WriteLine();
WriteLine("\nUpdating Name of Key 1");
itemEdit.edit(1, "name", "updated", db); // editing name
db.showDB();
WriteLine();
WriteLine("\nUpdating description of Key 1");
itemEdit.edit(1, "descr", "updated", dbPay); // editing description
dbPay.showEnumerableDB();
WriteLine();
WriteLine("\nUpdating childern of Key 1");
List <int> child = new List <int> {
3, 2, 1
};
itemEdit.editChildern(1, "childern", child, db); // editing children
db.showDB();
WriteLine();
WriteLine();
WriteLine("\nUpdating Payload of Key 'Thug3'");
List <string> payEdit = new List <string> {
"Updated", "the", "payload !"
};
itemEdit2.editPayload("Thug3", "payload", payEdit, dbString); // editing payload
dbString.showEnumerableDB();
WriteLine();
}
public void processValueQuery(Key key, out DBElement <Key, Value> value)
{
value = default(DBElement <Key, Value>);
if (db != null && db.Dictionary.Keys.Contains(key))
{
db.getValue(key, out value);
}
}
public static void Main(string[] args)
{
"Testing Item Editor Package".title('=');
Console.WriteLine();
DBEngine <int, DBElement <int, List <string> > > dbPay = new DBEngine <int, DBElement <int, List <string> > >();
DBElement <int, List <string> > elemPayload = new DBElement <int, List <string> >();
elemPayload.name = "Element4";
elemPayload.descr = "test element4";
elemPayload.timeStamp = DateTime.Now;
elemPayload.children.AddRange(new List <int> {
1, 2, 3
});
elemPayload.payload = new List <string>();
elemPayload.payload.AddRange(new List <string> {
"Project 2", " ", "demo", " ", "starts"
});
//elem.showElement();
dbPay.insert(4, elemPayload);
DBElement <int, List <string> > elemPayload2 = new DBElement <int, List <string> >();
elemPayload2.name = "Element5";
elemPayload2.descr = "test element5";
elemPayload2.timeStamp = DateTime.Now;
elemPayload2.children.AddRange(new List <int> {
98, 22, 35
});
elemPayload2.payload = new List <string>();
elemPayload2.payload.AddRange(new List <string> {
"we", "rock", "the", "world"
});
//elem.showElement();
dbPay.insert(5, elemPayload2);
dbPay.showEnumerableDB();
Console.WriteLine();
ItemEditor <int, string> itemEdit = new ItemEditor <int, string>();
itemEdit.edit(4, "name", "updated", dbPay);
itemEdit.edit(4, "descr", "updated", dbPay);
List <int> child = new List <int> {
3, 2, 1
};
itemEdit.editChildern(4, "childern", child, dbPay);
List <string> payLoad = new List <string> {
"Update", " ", "demo", " ", "starts"
};
itemEdit.editPayload(4, "pay-load", payLoad, dbPay);
dbPay.showEnumerableDB();
}
static void Main(string[] args)
{
"Testing DBElement Package".title('=');
WriteLine();
Write("\n --- Test DBElement<int,string> ---");
WriteLine();
DBElement <int, string> elem1 = new DBElement <int, string>();
Write(elem1.showElement <int, string>());
WriteLine();
DBElement <int, string> elem2 = new DBElement <int, string>("Darth Vader", "Evil Overlord");
elem2.payload = "The Empire strikes back!";
Write(elem2.showElement <int, string>());
WriteLine();
var elem3 = new DBElement <int, string>("Luke Skywalker", "Young HotShot");
elem3.children = new List <int> {
1, 2, 7
};
elem3.payload = "X-Wing fighter in swamp - Oh oh!";
Write(elem3.showElement <int, string>());
WriteLine();
Write("\n --- Test DBElement<string,List<string>> ---");
WriteLine();
DBElement <string, List <string> > newelem1 = new DBElement <string, List <string> >();
newelem1.name = "newelem1";
newelem1.descr = "test new type";
newelem1.payload = new List <string> {
"one", "two", "three"
};
Write(newelem1.showElement <string, List <string>, string>());
WriteLine();
DBElement <string, List <string> > newerelem1 = new DBElement <string, List <string> >();
newerelem1.name = "newerelem1";
newerelem1.descr = "same stuff";
newerelem1.children.Add("first_key");
newerelem1.children.Add("second_key");
newerelem1.payload = new List <string> {
"alpha", "beta", "gamma"
};
newerelem1.payload.AddRange(new[] { "delta", "epsilon" });
Write(newerelem1.showElement <string, List <string>, string>());
WriteLine();
Write("\n\n");
}
// clone function will create clone of element before do any changes.
public void clone()
{
dbElementCloned = new DBElement <Key, ListOfStrings>();
dbElementCloned.name = String.Copy(dbElement.name);
dbElementCloned.descr = String.Copy(dbElement.descr);
dbElementCloned.timeStamp = DateTime.Now;
dbElementCloned.children = new List <Key>();
dbElementCloned.children.AddRange(dbElement.children);
dbElementCloned.payload = dbElement.payload.clone() as ListOfStrings;
}
/*
* show DB factory data.
*/
public void showDBFactory()
{
foreach (Key key in dbStore.Keys)
{
Value value = dbStore[key];
DBElement<int, ListOfStrings> elem = value as DBElement<int, ListOfStrings>;
Write("\n\n -- key = {0} --", key);
elem.showElement();
}
}
void TestR4()
{
"\n1) Editing metadata".title();
"\nBefore editing metadata for key 1".title();
db.showDB();
WriteLine();
"\nAfter editing metadata for key 1".title();
iEditor = new ItemEditor <int, DBElement <int, string> >(db);
iEditor.editMetaData(1, "Sachin Tendulkar", "Cricket player"); //send the values to be edited to the editMetaData() function
db.showDB();
WriteLine();
"\n2) Adding children".title();
"\nBefore adding relationship(children) for key 2".title();
db.showDB();
WriteLine();
"\nAfter adding relationship(children) for Key 2".title();
iEditor.addrelationships(2, new List <int> {
4, 5
}); //send a new list with children to be added to a key
db.showDB();
WriteLine();
WriteLine();
"\n3) Deleting children".title();
"\nBefore deleting relationship(children) for key 2".title();
db.showDB();
WriteLine();
"\nAfter deleting relationship(children) to Key 2".title(); //send a new list with children to be deleted from a key
iEditor.deleteRelationships(2, new List <int> {
4, 5
});
db.showDB();
WriteLine();
WriteLine();
"\n4) Replacing value instance".title();
DBElement <int, string> elem = new DBElement <int, string>(); //create a new element for replacing value
elem.name = "Messi";
elem.payload = "Plays for Argentina";
elem.descr = "Football player";
elem.children.AddRange(new List <int> {
2
});
elem.timeStamp = DateTime.Now;
"\nBefore replacing the value instance for key 3".title();
db.showDB();
WriteLine();
"\nAfter replacing the value instance for key 3".title();
iEditor.replaceValueInstance(3, elem); //send value to be replaced for a key
db.showDB();
WriteLine();
}
//----< write simple db elements out to Console >------------------
public static void show <Key, Value, Data>(this DBEngine <Key, Value> db)
{
foreach (Key key in db.Keys())
{
Value value;
db.getValue(key, out value);
DBElement <Key, Data> elem = value as DBElement <Key, Data>;
Write("\n\n -- key = {0} --", key);
Write(elem.showElement());
}
}
//----< write details of element with simple Data to string >-----
public static string showElement <Key, Data>(this DBElement <Key, Data> elem)
{
StringBuilder accum = new StringBuilder();
accum.Append(elem.showMetaData());
if (elem.payload != null)
{
accum.Append(String.Format("\n payload: {0}", elem.payload.ToString()));
}
return(accum.ToString());
}
//----< write simple db elements out to Console >------------------
public static void showDictionaryData <Key, Value, Data>(this Dictionary <Key, Value> db)
{
foreach (Key key in db.Keys)
{
Value value;
value = db[key];
DBElement <int, List <string> > elem = value as DBElement <int, List <string> >;
Write("\n\n -- key = {0} --", key);
Write(elem.showElement());
}
}
//----< write enumerable db elements out to Console >--------------
public static void showEnumerable <Key, Value, Data, T>(this DBEngine <Key, Value> db)
where Data : IEnumerable <T>
{
foreach (Key key in db.Keys())
{
Value value;
db.getValue(key, out value);
DBElement <Key, Data> elem = value as DBElement <Key, Data>;
Write("\n\n -- key = {0} --", key);
Write(elem.showEnumerableElement <Key, Data, T>());
}
}
/*
* Add record in xml file.
* needs to provide input as key and value.
*/
public bool addRecord(Key key, DBElement <Key, Value> data)
{
if (!keyPresent(key))
{
addRecordInXml(key, data);
return(true);
}
else
{
return(false);
}
}
/*
* Add record in xml file.
* Input will be key and value pair.
*/
private void addRecordInXml(Key key, DBElement <Key, Value> record)
{
bool present = document.Descendants("elements").Any();
if (!present)
{
XElement element = new XElement("elements");
document.Root.Add(element);
}
// Add key-value pair under elements TAG.
XElement keyElement = new XElement("key", new XAttribute("id", key.ToString()));
XElement valueElement = new XElement("value");
XElement nameElement = new XElement("name", record.name);
XElement timeElement = new XElement("time", record.timeStamp.ToString());
XElement descrElement = new XElement("desc", record.descr);
XElement payLoadElement = new XElement("payload");
String payloadType = record.payload.GetType().ToString();
ListOfStrings payload = record.payload as ListOfStrings;
if (payload != null)
{
foreach (var item in payload.theWrappedData)
{
XElement payLoadChildElement = new XElement("item", item.ToString());
payLoadElement.Add(payLoadChildElement);
}
}
valueElement.Add(nameElement);
valueElement.Add(timeElement);
valueElement.Add(descrElement);
valueElement.Add(payLoadElement);
// add children in xml file.
List <Key> listChildren = record.children;
if (listChildren.Count > 0)
{
XElement children = new XElement("children");
foreach (var item in listChildren)
{
XElement xChildren = new XElement("item", item);
children.Add(xChildren);
}
valueElement.Add(children);
}
keyElement.Add(valueElement);
document.Element("noSqlDb").Element("elements").Add(keyElement);
document.Save(fileName);
}
// This function will edit time in item's metadata. New time will be provide in function argument.
public bool editByTime(ref DBEngine <Key, DBElement <Key, ListOfStrings> > dbEngine, Key key, DateTime newTime)
{
if (dbEngine.Dictionary.Keys.Contains(key))
{
dbElement = dbEngine.Dictionary[key];
clone();
dbElementCloned.timeStamp = newTime;
editDictionary(ref dbEngine, key);
return(true);
}
else
{
return(false);
}
}
// This function will edit payload details in metadata of item.
public bool editPayloadByListOfString(ref DBEngine <Key, DBElement <Key, ListOfStrings> > dbEngine, Key key, List <string> payload)
{
if (dbEngine.Dictionary.Keys.Contains(key))
{
dbElement = dbEngine.Dictionary[key];
clone();
dbElementCloned.payload.theWrappedData = payload;
editDictionary(ref dbEngine, key);
return(true);
}
else
{
return(false);
}
}
void testR2()
{
"Demonstrating Requirement #2".title();
DBElement <int, String> elem = new DBElement <int, string>();
elem.name = "text element";
elem.descr = "descr";
elem.timeStamp = DateTime.Now;
elem.payload = "elem's payload";
elem.children.AddRange(new [] { 1, 2, 3 });
elem.showElement();
db.insert(1, elem);
db.showDB();
WriteLine();
}
