question: private char foldCase ( char ch ) { if ( ch < 128 ) { if ( 'A' <= ch && ch <= 'Z' ) { return ( char ) ( ch + ( 'a' - 'A' ) ) ; } return ch ; } return Character . toLowerCase ( Character . toUpperCase ( ch ) ) ; }
target:  This isn't equivalent to either of ICU's u_foldCase case folds, and thus any of the Unicode case folds, but it's what the RI uses.