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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 collect_usage_pieces(self, ctx):
 """Returns all the pieces that go into the usage line and returns it as a list of strings. """

        rv = [self.options_metavar]
        for param in self.get_params(ctx):
            rv.extend(param.get_usage_pieces(ctx))
        return rv