class_docstr: UniversalEnhancer context window
  
  This is a context window which keeps a process open.  Should allow
  for multiple requests without launching new java processes each time.
code: def process(self, doc):
      request = build_enhancer_request(
          doc, self.language, self.pronouns_pattern
      )
      return self.process_request(request)
  
file_path: stanza/stanza/server/ud_enhancer.py
imports: import stanza
  from stanza.protobuf import DependencyEnhancerRequest, Document, Language
  from stanza.server.java_protobuf_requests import send_request, add_sentence, JavaProtobufContext
label_desc: Use image node_id 2 for calling the UniversalEnhancer obj's underlying member method code with example usage: obj.process(doc) and returns: self