class_docstr: Error for representing possibly multiple errors on engines
docstr: render one or all of my tracebacks to a list of lines
docstr_tok: ["render","one","or","all","of","my","tracebacks","to","a","list","of","lines"]
code: def render_traceback(self, excid=None):
      """render one or all of my tracebacks to a list of lines"""
      lines = []
      if excid is None:
          for en, ev, etb, ei in self.elist[: self.tb_limit]:
              lines.append(self._get_engine_str(ei) + ":")
              lines.extend(
                  (etb or "No traceback available").splitlines()
              )
              lines.append("")
          if len(self.elist) > self.tb_limit:
              lines.append(
                  "... %i more exceptions ..."
                  % (len(self.elist) - self.tb_limit)
              )
      else:
          try:
              en, ev, etb, ei = self.elist[excid]
          except:
              raise IndexError(
                  "an exception with index %i does not exist" % excid
              )
          else:
              lines.append(self._get_engine_str(ei) + ":")
              lines.extend(
                  (etb or "No traceback available").splitlines()
              )
  
      return lines
  
imports: import builtins
  import sys
  import traceback
label_desc: Use image node_id 5 for calling the CompositeError obj's underlying member method code with example usage: obj.render_traceback(excid) and returns: lines