code: def init_b(self):
      # initializer for a tensor of unique values
      return lambda shape: np.arange(np.prod(shape)).reshape(shape)
  
imports: from mock import Mock
  import numpy
  import pytest
  import theano
  from lasagne.layers import InputLayer, standardize, get_output, get_all_params
  from lasagne.utils import floatX
label_desc: Use image node_id 2 for calling the TestBiasLayer obj's underlying member method code with example usage: obj.init_b() and returns: function