code: def merge(self, m, tables):
      if not hasattr(self, "mergeMap"):
          log.info("Don't know how to merge '%s'.", self.tableTag)
          return NotImplemented
  
      logic = self.mergeMap
  
      if isinstance(logic, dict):
          return m.mergeObjects(self, self.mergeMap, tables)
      else:
          return logic(tables)
  
imports: from fontTools.ttLib.tables.DefaultTable import DefaultTable
  import logging
label_desc: Use image node_id 3 for calling a global function with example usage: merge(m, tables) and returns: NotImplemented, m, logic