code: def test_train_no_valid(self):
      trainer = Trainer(self.model, preprocessor=self.p)
      trainer.train(self.x_train, self.y_train)
  
file_path: anago/tests/test_trainer.py
imports: import os
  import unittest
  from anago.utils import load_data_and_labels
  from anago.models import BiLSTMCRF, save_model
  from anago.preprocessing import IndexTransformer
  from anago.trainer import Trainer
label_desc: Use image node_id 4 for calling the TestTrainer obj's underlying member method code with example usage: obj.test_train_no_valid() without return types