def parse_rfc822( filename: str ) -> dict[ str, str ]:

    d = {}

    with open( filename, "r" ) as f:
        for line in f:
            parts = line.split( ": ", 1 ) # incl. the space

            # drop line endings
            if parts[1][-1] == '\n':
                parts[1] = parts[1][:-1]

            d[parts[0]] = parts[1]
    return d

import run_tests