class_docstr: Graph Optimizer that merges different cond ops 
class_docstr_tok: ["Graph","Optimizer","that","merges","different","cond","ops"]
code: def add_requirements(self, fgraph):
      fgraph.add_feature(gof.toolbox.ReplaceValidate())
  
imports: from __future__ import absolute_import, print_function, division
  from copy import deepcopy
  from theano.compat import izip
  import logging
  import numpy
  import theano.tensor
  from theano.tensor import TensorType
  from theano import gof
  from theano.gof import Op, Apply
  from six import iteritems
  from six.moves import xrange
  from theano.compile import optdb
  from theano.tensor import opt
  from theano.scan_module.scan_utils import clone
label_desc: Use image node_id 1 for calling the CondMerge obj's underlying member method code with example usage: obj.add_requirements(fgraph) without return types