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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 format_specifier(ireq):
 """ Generic formatter for pretty printing the specifier part of InstallRequirements to the terminal. """

    # TODO: Ideally, this is carried over to the pip library itself
    specs = ireq.specifier._specs if ireq.req is not None else []
    specs = sorted(specs, key=lambda x: x._spec[1])
    return ",".join(str(s) for s in specs) or "<any>"