code: def test_from_str(self):
      self.assertEqual(
          ClassificationType.SINGLE_LABEL,
          ClassificationType.from_str("single-label"),
      )
      self.assertEqual(
          ClassificationType.MULTI_LABEL,
          ClassificationType.from_str("multi-label"),
      )
  
imports: import unittest
  import scipy
  import numpy
  from small_text.classifiers.classification import SklearnClassifier, ConfidenceEnhancedLinearSVC
  from small_text.query_strategies.base import ClassificationType, constraints
  from small_text.query_strategies.strategies import RandomSampling
  from tests.utils.datasets import random_sklearn_dataset
label_desc: Use image node_id 1 for calling the ClassificationTypeTest obj's underlying member method code with example usage: obj.test_from_str() without return types