class_docstr: This annotator base class hosts a lightweight server that accepts
  annotation requests from CoreNLP.
  Each annotator simply defines 3 functions: requires, provides and annotate.
  
  This class takes care of defining appropriate endpoints to interface
  with CoreNLP.
docstr: Requires has to specify all the annotations required before we
  are called.
docstr_tok: ["Requires","has","to","specify","all","the","annotations","required","before","we","are","called","."]
code: def requires(self):
      """
      Requires has to specify all the annotations required before we
      are called.
      """
      raise NotImplementedError()
  
file_path: stanza/stanza/server/annotator.py
imports: import io
  from multiprocessing import Process
  from http.server import BaseHTTPRequestHandler, HTTPServer
  from http import client
  from stanza.protobuf import Document, parseFromDelimitedString, writeToDelimitedString
label_desc: Use image node_id 2 for calling the Annotator obj's underlying member method code with example usage: obj.requires() without return types