message: minor changes in tensor_shape
diff: @@ -245,7 +245,10 @@ class Dimension(object):
  Returns:
  True if this Dimension and `other` are compatible.
  """
  + try:
  other = as_dimension(other)
  + except (TypeError, ValueError):
  + return NotImplemented
  return (self._value is None or other.value is None or
  self._value == other.value)
  @@ -293,7 +296,10 @@ class Dimension(object):
  ValueError: If `self` and `other` are not compatible (see
  is_compatible_with).
  """
  + try:
  other = as_dimension(other)
  + except (TypeError, ValueError):
  + return NotImplemented
  self.assert_is_compatible_with(other)
  if self._value is None:
  return Dimension(other.value)
  @@ -322,7 +328,10 @@ class Dimension(object):
  Returns:
  A Dimension whose value is the sum of `self` and `other`.
  """
  + try:
  other = as_dimension(other)
  + except (TypeError, ValueError):
  + return NotImplemented
  if self._value is None or other.value is None:
  return Dimension(None)
  else:
  @@ -361,7 +370,10 @@ class Dimension(object):
  Returns:
  A Dimension whose value is the subtraction of `other` from `self`.
  """
  + try:
  other = as_dimension(other)
  + except (TypeError, ValueError):
  + return NotImplemented
  if self._value is None or other.value is None:
  return Dimension(None)
  else:
  