docstr: Return a list of relations which this processor can produce
docstr_tok: ["Return","a","list","of","relations","which","this","processor","can","produce"]
code: def get_known_relations(self):
      """
      Return a list of relations which this processor can produce
      """
      keys = [
          k
          for k in self.vocab["deprel"]._unit2id.keys()
          if k not in VOCAB_PREFIX
      ]
      return keys
  
file_path: stanza/stanza/pipeline/depparse_processor.py
imports: import torch
  from stanza.models.common import doc
  from stanza.models.common.utils import unsort
  from stanza.models.common.vocab import VOCAB_PREFIX
  from stanza.models.depparse.data import DataLoader
  from stanza.models.depparse.trainer import Trainer
  from stanza.pipeline._constants import *
  from stanza.pipeline.processor import UDProcessor, register_processor
  from stanza.pipeline.external.corenlp_converter_depparse import ConverterDepparse
label_desc: Use image node_id 4 for calling the DepparseProcessor obj's underlying member method code with example usage: obj.get_known_relations() and returns: keys