class_docstr: DmlCorpus implements a collection of articles. It is initialized via a DmlConfig
  object, which holds information about where to look for the articles and how
  to process them.
  
  Apart from being a regular corpus (bag-of-words iterable with a `len()` method),
  DmlCorpus has methods for building a dictionary (mapping between words and
  their ids).
docstr: Return metadata for article no. `docNo`.
docstr_tok: ["Return","metadata","for","article","no",".","`","docNo","`","."]
code: def getMeta(self, docNo):
      """
      Return metadata for article no. `docNo`.
      """
      sourceId, uri = self.documents[docNo]
      source = self.config.sources[sourceId]
      return source.getMeta(uri)
  
imports: import logging
  import os.path
  from gensim import interfaces, matutils
  import dictionary
label_desc: Use image node_id 11 for calling the DmlCorpus obj's underlying member method code with example usage: obj.getMeta(docNo) and returns: source