class_docstr: Base class for the neural UD Processors (tokenize,mwt,pos,lemma,depparse,sentiment,constituency) 
class_docstr_tok: ["Base","class","for","the","neural","UD","Processors","(","tokenize",",","mwt",",","pos",",","lemma",",","depparse",",","sentiment",",","constituency",")"]
code: def pretrain(self):
      return self._pretrain
  
imports: from abc import ABC, abstractmethod
  from stanza.models.common.doc import Document
  from stanza.pipeline.registry import NAME_TO_PROCESSOR_CLASS, PIPELINE_NAMES, PROCESSOR_VARIANTS
label_desc: Use image node_id 5 for calling the UDProcessor obj's underlying member method code with example usage: obj.pretrain() and returns: self