code: def test_filter_string_regex(dataframe):
      df = dataframe.change_type("Bell__Chart", str).filter_string(
          column_name="Bell__Chart",
          search_string="1.",
          regex=False,
      )
  
      assert len(df) == 3
  
imports: import pytest
label_desc: Use image node_id 4 for calling a global function with example usage: test_filter_string_regex(dataframe) without return types