question: public void write ( char cbuf [ ] , int off , int len ) { if ( ( off < 0 ) || ( off > cbuf . length ) || ( len < 0 ) || ( ( off + len ) > cbuf . length ) || ( ( off + len ) < 0 ) ) { throw new IndexOutOfBoundsException ( ) ; } else if ( len == 0 ) { return ; } buf . append ( cbuf , off , len ) ; }
target:  Write a portion of an array of characters.