code: def test_only_split_on_cr_lf(self):
      # The unicode line splitter splits on unicode linebreaks, which are
      # more numerous than allowed by the email RFCs; make sure we are only
      # splitting on those two.
      for parser in self.parsers:
          with self.subTest(parser=parser.__name__):
              msg = parser(
                  "Next-Line: not\x85broken\r\n"
                  "Null: not\x00broken\r\n"
                  "Vertical-Tab: not\vbroken\r\n"
                  "Form-Feed: not\fbroken\r\n"
                  "File-Separator: not\x1Cbroken\r\n"
                  "Group-Separator: not\x1Dbroken\r\n"
                  "Record-Separator: not\x1Ebroken\r\n"
                  "Line-Separator: not\u2028broken\r\n"
                  "Paragraph-Separator: not\u2029broken\r\n"
                  "\r\n",
                  policy=default,
              )
              self.assertEqual(
                  msg.items(),
                  [
                      ("Next-Line", "not\x85broken"),
                      ("Null", "not\x00broken"),
                      ("Vertical-Tab", "not\vbroken"),
                      ("Form-Feed", "not\fbroken"),
                      ("File-Separator", "not\x1Cbroken"),
                      ("Group-Separator", "not\x1Dbroken"),
                      ("Record-Separator", "not\x1Ebroken"),
                      ("Line-Separator", "not\u2028broken"),
                      ("Paragraph-Separator", "not\u2029broken"),
                  ],
              )
              self.assertEqual(msg.get_payload(), "")
  
imports: import io
  import email
  import unittest
  from email.message import Message, EmailMessage
  from email.policy import default
  from test.test_email import TestEmailBase
label_desc: Use image node_id 1 for calling the TestParserBase obj's underlying member method code with example usage: obj.test_only_split_on_cr_lf() without return types