code: def test_utf8_bom():
      tree = parso.parse(unicode_bom + "a = 1")
      expr_stmt = tree.children[0]
      assert expr_stmt.start_pos == (1, 0)
  
      tree = parso.parse(unicode_bom + "\n")
      endmarker = tree.children[0]
      parts = list(endmarker._split_prefix())
      assert [p.type for p in parts] == ["bom", "newline", "spacing"]
      assert [p.start_pos for p in parts] == [(1, 0), (1, 0), (2, 0)]
      assert [p.end_pos for p in parts] == [(1, 0), (2, 0), (2, 0)]
  
imports: from itertools import zip_longest
  from codecs import BOM_UTF8
  import pytest
  import parso
label_desc: Use image node_id 3 for calling a global function with example usage: test_utf8_bom() without return types