code: def test_assemble_block():
      df = pd.DataFrame(
          {"mu": [0.2], "sig": [0.1], "values": [[0.1, 0.3]]}
      )
      block = assemble_block(
          n_rows=2,
          n_cols=1,
          pdf=df,
          cov_matrix=np.array([]),
          row_mask=np.array([]),
      )
      assert np.allclose(block, np.array([[-1.0], [1.0]]))
  
imports: from glow.wgr.model_functions import *
  from glow.wgr.model_functions import _prepare_covariates, _prepare_labels_and_warn
  import math
  import numpy
  import pandas
  from pyspark.sql import Row
  import pytest
  from sklearn.linear_model import LogisticRegression
  from sklearn.datasets import load_breast_cancer
label_desc: Use image node_id 4 for calling a global function with example usage: test_assemble_block() without return types