parameters: (tensor, tag=None)
return_statement: return summary.histogram(tag, tensor)
docstring: Add a summary operation for the histogram of a tensor.
  
    Args:
      tensor: The tensor to summarize.
      tag: The tag to use, if None then use tensor's op's name.
  
    Returns:
      The created histogram summary.
  
    Raises:
      ValueError: If the tag is already in use.
docstring_summary: Add a summary operation for the histogram of a tensor.
docstring_tokens: Add a summary operation for the histogram of a tensor .
function: def _add_histogram_summary(tensor, tag=None):
    """Add a summary operation for the histogram of a tensor.
  
    Args:
      tensor: The tensor to summarize.
      tag: The tag to use, if None then use tensor's op's name.
  
    Returns:
      The created histogram summary.
  
    Raises:
      ValueError: If the tag is already in use.
    """
    tag = tag or '%s_summary' % tensor.op.name
    return summary.histogram(tag, tensor)
function_tokens: def _add_histogram_summary ( tensor , tag = None ) : tag = tag or '%s_summary' % tensor . op . name return summary . histogram ( tag , tensor )