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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 _get_encoder_method(stream_type):
 """A function to get the python type to device cloud type converter function. :param stream_type: The streams data type :return: A function that when called with the python object will return the serializable type for sending to the cloud. If there is no function for the given type, or the `stream_type` is `None` the returned function will simply return the object unchanged. """

    if stream_type is not None:
        return DSTREAM_TYPE_MAP.get(stream_type.upper(), (lambda x: x, lambda x: x))[1]
    else:
        return lambda x: x