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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 summarize_tensors(tensor_dict, tag=None):
 """Summarize the tensors. Args: tensor_dict: a dictionary of tensors. tag: name scope of the summary; defaults to tensors/. """

  if tag is None:
    tag = "tensors/"

  for t_name in list(tensor_dict):
    t = tensor_dict[t_name]
    tf.summary.histogram(tag + t_name, t)