Implementing a mergable programmatic lexer

In the documentation is stated:

Quote:

A mergable programmatic lexer is made by creating a class that implements the IMergableLexer interface, although inheriting the MergableLexerBase class is the easiest way to accomplish this. When inheriting MergableLexerBase, the only method we are required to implement is the CreateToken method.

CreateToken doesnt have a reader as parameter; maybe GetNextToeken is meant, just as in a Simple language sample?