public void Should_store_default_value_for_string()
 {
     IDataType str = new DataTypeString();
       Assert.AreEqual("", str.Value);
       str.Value ="value";
       Assert.AreEqual(val, str.Value);
 }
 public void Should_have_data_types()
 {
     IDataType dt = new DataTypeString();
       Assert.AreEqual(DATA_TYPE.STRING, dt.DataType);
       dt = new DataTypeNumeric();
       Assert.AreEqual(DATA_TYPE.NUMERIC, dt.DataType);
 }