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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def highlight(__text: str, *, lexer: str = 'diff', formatter: str = 'terminal') -> str: """Highlight text highlighted using ``pygments``. Returns text untouched if colour output is not enabled. See also: :pypi:`Pygments` Args: __text: Text to highlight lexer: Jinja lexer to use formatter: Jinja formatter to use Returns: Syntax highlighted output, when possible """

    if sys.stdout.isatty():
        lexer = get_lexer_by_name(lexer)
        formatter = get_formatter_by_name(formatter)
        __text = pyg_highlight(__text, lexer, formatter)
    return __text