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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 add_histogram_summary(self, x, tag=None):
 """Add a summary operation to visualize the histogram of x's values."""

    if not self.summary_collections:
      return
    with self.g.as_default():
      tag = tag or _tag_for(x.name)
      summary = tf.summary.histogram(
          tag, x, collections=self.summary_collections)
      return summary