@Nonnull
  public EChange add (@Nonnull final Map.Entry <String, String> aEntry)
  {
    return add (aEntry.getKey (), aEntry.getValue ());
  }
@Nonnull
  public EChange add (@Nonnull final Map.Entry <String, String> aEntry)
  {
    return add (aEntry.getKey (), aEntry.getValue ());
  }
@ Nonnull public EChange add ( @ Nonnull final Map . Entry < String , String > aEntry ) { return add ( aEntry . getKey ( ) , aEntry . getValue ( ) ) ; }
Add a new variable.

@param aEntry
The entry to be added - key is the variable name and value is the
variable value. May not be <code>null</code>.
@return {@link EChange#UNCHANGED} if a variable with the same name is
already present. Never <code>null</code>.
Add a new variable .