def _quote(data):
data = data.replace(b'<STR_LIT:\\>', b'<STR_LIT>')<EOL>data = data.replace(b'<STR_LIT:">', b'<STR_LIT>')<EOL>return data<EOL>
Prepare a string for quoting for DIGEST-MD5 challenge or response.

    Don't add the quotes, only escape '"' and "\\" with backslashes.

    :Parameters:
        - `data`: a raw string.
    :Types:
        - `data`: `bytes`

    :return: `data` with '"' and "\\" escaped using "\\".
    :returntype: `bytes`