code: def test_is_fitted(self):
      model = MLPAlgorithm(self.params)
      self.assertFalse(model.is_fitted())
      model.fit(self.X, self.y)
      self.assertTrue(model.is_fitted())
  
imports: import unittest
  import tempfile
  import json
  import numpy
  import pandas
  import os
  from numpy.testing import assert_almost_equal
  from sklearn import datasets
  from sklearn import preprocessing
  from supervised.algorithms.nn import MLPAlgorithm, MLPRegressorAlgorithm
  from supervised.utils.metric import Metric
label_desc: Use image node_id 3 for calling the MultiClassNeuralNetworkAlgorithmTest obj's underlying member method code with example usage: obj.test_is_fitted() without return types