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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(self):
 """Collect the elements in an PRDD and concatenate the partition."""

        # The order of the frame order appends is based on the implementation
        # of reduce which calls our function with
        # f(valueToBeAdded, accumulator) so we do our reduce implementation.
        def append_frames(frame_a, frame_b):
            return frame_a.append(frame_b)
        return self._custom_rdd_reduce(append_frames)