Remove() public method

Removes the word (and its corresponding a list of positions) from this FrequencyDictionary. This method does nothing if the key is not in the FrequencyDictionary.
public Remove ( string str ) : void
str string the word that needs to be removed
return void
 public void EqualsTest()
 {
     string str = chain.ToString();
     var alphabet1 = new FrequencyDictionary(str);
     var alphabet2 = new FrequencyDictionary(chain);
     Assert.True(alphabet1.Equals(alphabet2));
     alphabet1.Remove(alphabet1.GetWord(1));
     Assert.True(!alphabet1.Equals(alphabet2));
 }
 public void RemoveTest()
 {
     var alphabet = new FrequencyDictionary(chain);
     string[] words = { "A", "G", "C", "T", "WORD", "AG" };
     alphabet.Remove(words[0]);
     Assert.True(!alphabet.Contains(words[0]));
     alphabet.Remove(words[1]);
     Assert.True(!alphabet.Contains(words[1]));
     alphabet.Remove(words[2]);
     Assert.True(!alphabet.Contains(words[2]));
     alphabet.Remove(words[3]);
     Assert.True(!alphabet.Contains(words[3]));
     Assert.True(alphabet.Count == 0);
 }