code: def get(self, document=None, plugin=None):
          
          if plugin is not None:
              if document is None:
                  documents_list = {}
                  for key in self.documents.keys():
                      if self.documents[key].plugin == plugin:
                          documents_list[key] = self.documents[key]
                  return documents_list
              else:
                  if document in self.documents.keys():
                      if self.documents[document].plugin == plugin:
                          return self.documents[document]
                      else:
                          return None
                  else:
                      return None
          else:
              if document is None:
                  return self.documents
              else:
                  if document in self.documents.keys():
                      return self.documents[document]
                  else:
                      return None
docs: Get one or more documents.
  
          :param document: Name of the document
          :type document: str
          :param plugin: Plugin object, under which the document was registered
          :type plugin: GwBasePattern