def test_headersMultiline(self):
        """
        Line folded headers are handled by L{HTTPChannel} by replacing each
        fold with a single space by the time they are made available to the
        L{Request}. Any leading whitespace in the folded lines of the header
        value is preserved.

        See RFC 7230 section 3.2.4.
        """
        processed = []

        class MyRequest(http.Request):
            def process(self):
                processed.append(self)
                self.finish()

        requestLines = [
            b"GET / HTTP/1.0",
            b"nospace: ",
            b" nospace\t",
            b"space:space",
            b" space",
            b"spaces: spaces",
            b"  spaces",
            b"   spaces",
            b"tab: t",
            b"\ta",
            b"\tb",
            b"",
            b"",
        ]

        self.runRequest(b"\n".join(requestLines), MyRequest, 0)
        [request] = processed
        # All leading and trailing whitespace is stripped from the
        # header-value.
        self.assertEqual(
            request.requestHeaders.getRawHeaders(b"nospace"),
            [b"nospace"],
        )
        self.assertEqual(
            request.requestHeaders.getRawHeaders(b"space"),
            [b"space  space"],
        )
        self.assertEqual(
            request.requestHeaders.getRawHeaders(b"spaces"),
            [b"spaces   spaces    spaces"],
        )
        self.assertEqual(
            request.requestHeaders.getRawHeaders(b"tab"),
            [b"t \ta \tb"],
        )

        Line folded headers are handled by L{HTTPChannel} by replacing each
        fold with a single space by the time they are made available to the
        L{Request}. Any leading whitespace in the folded lines of the header
        value is preserved.

        See RFC 7230 section 3.2.4.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_http.py