class_docstr: Error for representing possibly multiple errors on engines
code: def __str__(self):
      s = str(self.msg)
      for en, ev, etb, ei in self.elist[: self.tb_limit]:
          engine_str = self._get_engine_str(ei)
          s = s + "\n" + engine_str + en + ": " + str(ev)
      if len(self.elist) > self.tb_limit:
          s = s + "\n.... %i more exceptions ..." % (
              len(self.elist) - self.tb_limit
          )
      return s
  
imports: import builtins
  import sys
  import traceback
label_desc: Use image node_id 3 for calling the CompositeError obj's underlying member method code with example usage: obj.__str__() and returns: s