code: def register_output(self, output, identifier="default"):
      self._output_identifier_set.add(identifier)
      tf.add_to_collection(
          "openrec.tf1.recommender.outputs." + identifier, output
      )
  
imports: import tensorflow
  import numpy
  import os
label_desc: Use image node_id 7 for calling the _RecommenderGraph obj's underlying member method code with example usage: obj.register_output(output, identifier) without return types