class_docstr: PEP 3120 makes UTF-8 the default encoding for source code
  [default encoding].
  
  PEP 263 specifies how that can change on a per-file basis. Either the first
  or second line can contain the encoding line [encoding first line]
  [encoding second line]. If the file has the BOM marker it is considered UTF-8
  implicitly [BOM]. If any encoding is specified it must be UTF-8, else it is
  an error [BOM and utf-8][BOM conflict].
class_docstr_tok: ["PEP","3120","makes","UTF-8","the","default","encoding","for","source","code","[","default","encoding","]",".","PEP","263","specifies","how","that","can","change","on","a","per-file","basis",".","Either","the","first","or","second","line","can","contain","the","encoding","line","[","encoding","first","line","]","[","encoding","second","line","]",".","If","the","file","has","the","BOM","marker","it","is","considered","UTF-8","implicitly","[","BOM","]",".","If","any","encoding","is","specified","it","must","be","UTF-8",",","else","it","is","an","error","[","BOM","and","utf-8","]","[","BOM","conflict","]","."]
code: def test_encoding_on_first_line(self):
      encoding = "Latin-1"
      source = self.create_source(encoding)
      self.run_test(source)
  
imports: from test.test_importlib import util
  import codecs
  import importlib.util
  import re
  import types
  import unicodedata
  import unittest
  import warnings
label_desc: Use image node_id 5 for calling the EncodingTest obj's underlying member method code with example usage: obj.test_encoding_on_first_line() without return types