def detect_format(filename):
if "<STR_LIT>" in filename:<EOL><INDENT>return "<STR_LIT>"<EOL><DEDENT>if "<STR_LIT>" in filename:<EOL><INDENT>return "<STR_LIT>"<EOL><DEDENT>return "<STR_LIT>"<EOL>
Tries to figure out the type of the file. Return 'warc' for
    WARC files and 'arc' for ARC files