code: def test_opacity():
      doc = fitz.open()
      page = doc.new_page()
  
      annot1 = page.add_circle_annot((50, 50, 100, 100))
      annot1.set_colors(fill=(1, 0, 0), stroke=(1, 0, 0))
      annot1.set_opacity(2 / 3)
      annot1.update(blend_mode="Multiply")
  
      annot2 = page.add_circle_annot((75, 75, 125, 125))
      annot2.set_colors(fill=(0, 0, 1), stroke=(0, 0, 1))
      annot2.set_opacity(1 / 3)
      annot2.update(blend_mode="Multiply")
      outfile = f"{scriptdir}/resources/opacity.pdf"
      doc.save(outfile, expand=True, pretty=True)
      print("saved", outfile)
  
imports: import io
  import os
  import fitz
  import pickle
label_desc: Use image node_id 21 for calling a global function with example usage: test_opacity() without return types