code: def setUp(self):
      self._state = {
          torchbearer.Y_TRUE: Variable(
              torch.FloatTensor([0.8, 0.2, 0.0, 0.4, 0.3, 0.7])
          ),
          torchbearer.Y_PRED: Variable(
              torch.FloatTensor([0.9, 0.1, 0.1, 0.7, 0.5, 0.6])
          ),
      }
      self._targets = [0.01, 0.01, 0.01, 0.09, 0.04, 0.01]
      self._metric = MeanSquaredError().root
  
imports: import unittest
  import torch
  from torch.autograd import Variable
  import torchbearer
  from torchbearer.metrics import Loss, Epoch, CategoricalAccuracy, TopKCategoricalAccuracy, BinaryAccuracy, MeanSquaredError
label_desc: Use image node_id 1 for calling the TestMeanSquaredError obj's underlying member method code with example usage: obj.setUp() without return types