code: def to_string(self):
      layer_scope_name = self.layer_scope().name
      out_str = "\033[42m[Layer]\033[0m {}".format(layer_scope_name)
      if not self._op._variables_created:
          out_str += " \033[46m(input undecided)\033[0m"
          return out_str
      return out_str
  
imports: from __future__ import absolute_import, print_function
  from abc import ABCMeta, abstractmethod
  import numpy
  import tensorflow
  from six import with_metaclass
  from niftynet.engine.application_variables import RESTORABLE
label_desc: Use image node_id 6 for calling the Layer obj's underlying member method code with example usage: obj.to_string() and returns: out_str, out_str