code: def init_alpha(self):
      # initializer for a tensor of unique values
      return lambda shape: floatX(
          (np.arange(np.prod(shape)).reshape(shape))
          / floatX(np.prod(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 TestParametricRectifierLayer obj's underlying member method code with example usage: obj.init_alpha() and returns: function