question: public java . lang . StringBuffer reverse ( ) { internal = internal . reverse ( ) ; return this ; }
target:  The character sequence contained in this string buffer is replaced by the reverse of the sequence. Let n be the length of the old character sequence, the one contained in the string buffer just prior to execution of the reverse method. Then the character at index k in the new character sequence is equal to the character at index n-k-1 in the old character sequence.