code: def test_group_textblocks_based_on_category():
      page_layout = load_pdf("tests/fixtures/io/example.pdf")[0]
  
      pdf_blocks = group_textblocks_based_on_category(page_layout)
  
      assert len(pdf_blocks) == 3
  
imports: from layoutparser import load_pdf
  from layoutparser.tools import generalized_connected_component_analysis_1d, simple_line_detection, group_textblocks_based_on_category
label_desc: Use image node_id 3 for calling a global function with example usage: test_group_textblocks_based_on_category() without return types