code: def unify_walk(fv, v, U):
      """
      Both variables are unified.
  
      """
      v = U[v]
      return U.merge(v, fv)
  
imports: from __future__ import absolute_import, print_function, division
  from copy import copy
  from functools import partial
  from theano.gof.utils import ANY_TYPE, comm_guard, FALL_THROUGH, iteritems
label_desc: Use image node_id 7 for calling a global function with example usage: unify_walk(fv, v, U) and returns: U