def wheel_version(source_dir):<EOL>
try:<EOL><INDENT>dist = [d for d in pkg_resources.find_on_path(None, source_dir)][<NUM_LIT:0>]<EOL>wheel_data = dist.get_metadata('<STR_LIT>')<EOL>wheel_data = Parser().parsestr(wheel_data)<EOL>version = wheel_data['<STR_LIT>'].strip()<EOL>version = tuple(map(int, version.split('<STR_LIT:.>')))<EOL>return version<EOL><DEDENT>except Exception:<EOL><INDENT>return None<EOL><DEDENT>
Return the Wheel-Version of an extracted wheel, if possible.

Otherwise, return None if we couldn't parse / extract it.