code: def setUp(self):
      self._metric_function = Mock(return_value="test")
      self._metric = BatchLambda("test", self._metric_function)
      self._states = [
          {
              torchbearer.Y_TRUE: Variable(torch.FloatTensor([1])),
              torchbearer.Y_PRED: Variable(torch.FloatTensor([2])),
          },
          {
              torchbearer.Y_TRUE: Variable(torch.FloatTensor([3])),
              torchbearer.Y_PRED: Variable(torch.FloatTensor([4])),
          },
          {
              torchbearer.Y_TRUE: Variable(torch.FloatTensor([5])),
              torchbearer.Y_PRED: Variable(torch.FloatTensor([6])),
          },
      ]
  
imports: import unittest
  import torch
  from mock import Mock, call
  from torch.autograd import Variable
  import torchbearer
  from torchbearer.metrics import Metric, BatchLambda, EpochLambda, ToDict
label_desc: Use image node_id 1 for calling the TestBatchLambda obj's underlying member method code with example usage: obj.setUp() without return types