class_docstr: A trainer for training models. 
class_docstr_tok: ["A","trainer","for","training","models","."]
docstr: Return the tags known by this model
  
  Removes the S-, B-, etc, and does not include O
docstr_tok: ["Return","the","tags","known","by","this","model","Removes","the","S-",",","B-",",","etc",",","and","does","not","include","O"]
code: def get_known_tags(self):
      """
      Return the tags known by this model
  
      Removes the S-, B-, etc, and does not include O
      """
      tags = set()
      for tag in self.vocab["tag"].items(0):
          if tag in VOCAB_PREFIX:
              continue
          if tag == "O":
              continue
          if len(tag) > 2 and tag[:2] in ("S-", "B-", "I-", "E-"):
              tag = tag[2:]
          tags.add(tag)
      return sorted(tags)
  
imports: import sys
  import logging
  import torch
  from torch import nn
  from stanza.models.common.foundation_cache import NoTransformerFoundationCache
  from stanza.models.common.trainer import Trainer
  from stanza.models.common.vocab import VOCAB_PREFIX, VOCAB_PREFIX_SIZE
  from stanza.models.common import utils, loss
  from stanza.models.ner.model import NERTagger
  from stanza.models.ner.vocab import MultiVocab
  from stanza.models.common.crf import viterbi_decode
label_desc: Use image node_id 6 for calling the Trainer obj's underlying member method code with example usage: obj.get_known_tags() and returns: sorted