question: public boolean add ( CharSequence input , CharSequence output ) { final int length = input . length ( ) ; if ( ignoreCase ) { charsSpare . grow ( length ) ; final char [ ] buffer = charsSpare . chars ( ) ; for ( int i = 0 ; i < length ; ) { i += Character . toChars ( Character . toLowerCase ( Character . codePointAt ( input , i ) ) , buffer , i ) ; } spare . copyChars ( buffer , 0 , length ) ; } else { spare . copyChars ( input , 0 , length ) ; } if ( hash . add ( spare . get ( ) ) >= 0 ) { outputValues . add ( output ) ; return true ; } return false ; }
target:  Adds an input string and its stemmer override output to this builder.