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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 submit(self, value):
 """Submit a single or batch tensor to refine the streaming mean."""

    # Add a batch dimension if necessary.
    if value.shape.ndims == self._sum.shape.ndims:
      value = value[None, ...]
    return tf.group(
        self._sum.assign_add(tf.reduce_sum(value, 0)),
        self._count.assign_add(tf.shape(value)[0]))