def get_lexers(main_lex, exam_lex, tool_lex):
    """ gets all the lexer wrappers """
    if not main_lex:
        return None, None, None
    lexer = None
    if main_lex:
        if issubclass(main_lex, PromptLex):
            lexer = main_lex
        elif issubclass(main_lex, PygLex):
            lexer = PygmentsLexer(main_lex)

    if exam_lex:
        if issubclass(exam_lex, PygLex):
            exam_lex = PygmentsLexer(exam_lex)

    if tool_lex:
        if issubclass(tool_lex, PygLex):
            tool_lex = PygmentsLexer(tool_lex)

    return lexer, exam_lex, tool_lex
gets all the lexer wrappers