code: def test_numerics():
      # test data is pre-selected for numeric values
      data = DataFrame([[1, "a"], [2, "b"]])
      result = data.style.bar()._compute().ctx
      assert (0, 1) not in result
      assert (1, 1) not in result
  
imports: import io
  import numpy
  import pytest
  from pandas import NA, DataFrame, read_csv
label_desc: Use image node_id 14 for calling a global function with example usage: test_numerics() without return types