Following snippet is valid sphinx, but produce annoying warning highlights.
It considers any of ``\r``, ``\n``, and ``\r\n`` to be newlines.
Because of the ambiguity of an append operation ending in the character ``\r`` (it may be a bare ``\r`` or half of ``\r\n``), the last line of such an append operation will be buffered until the next append or flush.
Following snippet is valid sphinx, but produce annoying warning highlights.