def _last_bookmark(b0, b1):
n = [None, None]<EOL>_, _, n[<NUM_LIT:0>] = b0.rpartition("<STR_LIT::>")<EOL>_, _, n[<NUM_LIT:1>] = b1.rpartition("<STR_LIT::>")<EOL>for i in range(<NUM_LIT:2>):<EOL><INDENT>try:<EOL><INDENT>n[i] = int(n[i])<EOL><DEDENT>except ValueError:<EOL><INDENT>raise ValueError("<STR_LIT>".format(b0))<EOL><DEDENT><DEDENT>return b0 if n[<NUM_LIT:0>] > n[<NUM_LIT:1>] else b1<EOL>
Return the latest of two bookmarks by looking for the maximum
    integer value following the last colon in the bookmark string.