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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 largest_loop(self):
 """ Return the boundaries for the largest loop segment. This is just meant to be a reasonable default for various selectors and filters to work with, in the case that more than one loop is being modeled. If you want to be more precise, you'll have to override the selectors and filters in question. """

        from collections import namedtuple
        Loop = namedtuple('Loop', 'start end')
        largest_segment = sorted(
                self.loop_segments,
                key=lambda x: abs(x[1] - x[0]),
        )[-1]
        return Loop(*largest_segment)