code: def push_value(self, value):
      if not self.names_defined:
          self.names_defined = True
      target = self.next_target()
      if value == "stop_":
          return self.stop_push()
      target.append(value)
  
imports: import contextlib
  import gzip
  import json
  import re
label_desc: Use image node_id 3 for calling the LoopMMCIF obj's underlying member method code with example usage: obj.push_value(value) and returns: self