from tensorflow.python.ops import gen_resource_variable_ops

    return None

  @property
  def op(self):
    return self.get().op

  def _read_variable_op(self):
    if _enclosing_tpu_context() is None:
      return self._primary_var.read_value()
    v = gen_resource_variable_ops.read_variable_op(self.handle, self._dtype)
    return v

  def read_value(self):
    return self._read_variable_op()

  def assign(self, value, use_locking=None, name=None, read_value=False):
    del use_locking
    with _handle_graph(self.handle), self._assign_dependencies():
