def md5sum(self, f):
m = hashlib.md5()<EOL>fh = open(f, '<STR_LIT:r>')<EOL>while <NUM_LIT:1>:<EOL><INDENT>chunk = fh.read(BUF_SIZE)<EOL>if not chunk: break<EOL>m.update(chunk)<EOL><DEDENT>fh.close()<EOL>return m.hexdigest()<EOL>
md5sums a file, returning the hex digest

            Parameters:
                - f     filename string