code: def test_oc1():
      """Arbitrary calls to OC code to get coverage."""
      doc = fitz.open()
      ocg1 = doc.add_ocg("ocg1")
      ocg2 = doc.add_ocg("ocg2")
      ocg3 = doc.add_ocg("ocg3")
      ocmd1 = doc.set_ocmd(xref=0, ocgs=(ocg1, ocg2))
      doc.set_layer(-1)
      doc.add_layer("layer1")
      test = doc.get_layer()
      test = doc.get_layers()
      test = doc.get_ocgs()
      test = doc.layer_ui_configs()
      doc.switch_layer(0)
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_oc1() without return types