<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def highlight(code, lexer, formatter, outfile=None):
 """ Lex ``code`` with ``lexer`` and format it with the formatter ``formatter``. If ``outfile`` is given and a valid file object (an object with a ``write`` method), the result will be written to it, otherwise it is returned as a string. """

    return format(lex(code, lexer), formatter, outfile)