question: public static StreamEx < String > split ( CharSequence str , char delimiter , boolean trimEmpty ) { if ( str . length ( ) == 0 ) return of ( "" ) ; return of ( new CharSpliterator ( str , delimiter , trimEmpty ) ) ; }
target:  Creates a stream from the given input sequence around matches of the given character. <p> The stream returned by this method contains each substring of the input sequence that is terminated by supplied delimiter character or is terminated by the end of the input sequence. The substrings in the stream are in the order in which they occur in the input. If the trimEmpty parameter is true, trailing empty strings will be discarded and not encountered in the stream. <p> If the given delimiter character does not appear in the input then the resulting stream has just one element, namely the input sequence in string form. <p> If the input sequence is mutable, it must remain constant from the stream creation until the execution of the terminal stream operation. Otherwise, the result of the terminal stream operation is undefined.