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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 find_input(self, stream):
 """Find the input that responds to this stream. Args: stream (DataStream):
 The stream to find Returns: (index, None):
 The index if found or None """


        for i, input_x in enumerate(self.inputs):
            if input_x[0].matches(stream):
                return i