code: def test_pdf():
      pdf_layout = load_pdf("tests/fixtures/io/example.pdf")
      assert len(pdf_layout) == 1
  
      page_layout = pdf_layout[0]
      for attr_name in ["width", "height", "index"]:
          assert attr_name in page_layout.page_data
  
      assert len(set(ele.type for ele in page_layout)) == 3
  
imports: import numpy
  from layoutparser.elements import Interval, Rectangle, Quadrilateral, TextBlock, Layout
  from layoutparser import load_json, load_dict, load_csv, load_pdf
label_desc: Use image node_id 3 for calling a global function with example usage: test_pdf() without return types