code: def test_decompose_covariance(self):
      # Test if return_decomposed_components is correctly passed.
      NUM_VARIABLE = 10
      NUM_OBSERVATION = 200
  
      estimator = StructuredCovEstimator(
          scale_return=False, assume_centered=True, nan_option="fill"
      )
  
      X = np.random.rand(NUM_OBSERVATION, NUM_VARIABLE)
  
      F, cov_b, var_u = estimator.predict(
          X, is_price=False, return_decomposed_components=True
      )
  
      self.assertTrue(
          F is not None and cov_b is not None and var_u is not None
      )
  
file_path: qlib/tests/test_structured_cov_estimator.py
imports: import unittest
  import numpy
  from scipy.linalg import sqrtm
  from qlib.model.riskmodel import StructuredCovEstimator
label_desc: Use image node_id 3 for calling the TestStructuredCovEstimator obj's underlying member method code with example usage: obj.test_decompose_covariance() without return types