message: Explicitly disables variable inplace assignment methods.
  Need a story for eager, graph functions (both easy) and graphs (hard).
diff: @@ -768,6 +768,27 @@ class ResourceVariable(variables.Variable):
  else:
  return self.value()
  + def __iadd__(self, unused_other):
  + raise RuntimeError("Variable += value not supported.")
  +
  + def __isub__(self, unused_other):
  + raise RuntimeError("Variable -= value not supported.")
  +
  + def __imul__(self, unused_other):
  + raise RuntimeError("Variable *= value not supported.")
  +
  + def __idiv__(self, unused_other):
  + raise RuntimeError("Variable /= value not supported.")
  +
  + def __itruediv__(self, unused_other):
  + raise RuntimeError("Variable /= value not supported.")
  +
  + def __irealdiv__(self, unused_other):
  + raise RuntimeError("Variable /= value not supported.")
  +
  + def __ipow__(self, unused_other):
  + raise RuntimeError("Variable **= value not supported.")
  +
  def _dense_var_to_tensor(var, dtype=None, name=None, as_ref=False):
  return var._dense_var_to_tensor(dtype=dtype, name=name, as_ref=as_ref) # pylint: disable=protected-access
  