code: def test_pageids():
      assert doc.chapter_count == 7
      assert doc.last_location == (6, 1)
      assert doc.prev_location((6, 0)) == (5, 11)
      assert doc.next_location((5, 11)) == (6, 0)
      # Check page numbers have no gaps:
      i = 0
      for chapter in range(doc.chapter_count):
          for cpno in range(doc.chapter_page_count(chapter)):
              assert doc.page_number_from_location((chapter, cpno)) == i
              i += 1
  
imports: import os
  import fitz
label_desc: Use image node_id 2 for calling a global function with example usage: test_pageids() without return types