code: def test_train_called_with_state(self):
      self._metric.train()
      self._metric.process({"test": -1})
      self._metric._process_train.assert_called_with({"test": -1})
  
imports: import unittest
  from mock import Mock, call
  from torchbearer.metrics import RunningMean, Metric, RunningMetric, Mean, Std, Var
  import torch
label_desc: Use image node_id 2 for calling the TestRunningMetric obj's underlying member method code with example usage: obj.test_train_called_with_state() without return types