class_docstr: A trainer for training models. 
class_docstr_tok: ["A","trainer","for","training","models","."]
code: def update_lr(self, new_lr):
      utils.change_lr(self.optimizer, new_lr)
  
imports: import os
  import sys
  import numpy
  from collections import Counter
  import logging
  import torch
  from torch import nn
  import torch.nn.init
  import stanza.models.common.seq2seq_constant
  from stanza.models.common.foundation_cache import load_charlm
  from stanza.models.common.seq2seq_model import Seq2SeqModel
  from stanza.models.common.char_model import CharacterLanguageModelWordAdapter
  from stanza.models.common import utils, loss
  from stanza.models.lemma import edit
  from stanza.models.lemma.vocab import MultiVocab
label_desc: Use image node_id 6 for calling the Trainer obj's underlying member method code with example usage: obj.update_lr(new_lr) without return types