class_docstr: Helper class to make it easier to manage caching in `Bijector`.
class_docstr_tok: ["Helper","class","to","make","it","easier","to","manage","caching","in","`","Bijector","`","."]
docstr: Helper to merge which handles merging one value.
code: def _merge(self, old, new):
      """Helper to merge which handles merging one value."""
      if old is None:
          return new
      elif new is not None and old is not new:
          raise ValueError("Incompatible values: %s != %s" % (old, new))
      return old
  
imports: import abc
  import collections
  import contextlib
  import re
  import numpy
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor_shape
  from tensorflow.python.framework import tensor_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import check_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops.distributions import util
  from tensorflow.python.util import object_identity
label_desc: Use image node_id 6 for calling the _Mapping obj's underlying member method code with example usage: obj._merge(old, new) and returns: old, new