question: public static void appendEscapedTextToBuilder ( StringBuilder out , String item , char separator ) { for ( int i = 0 ; i < item . length ( ) ; i ++ ) { char ch = item . charAt ( i ) ; if ( ch == '\\' || ch == separator ) { out . append ( '\\' ) ; } out . append ( ch ) ; } }
target:  writes chars from item to out, backslash escaping as needed based on separator --  but does not append the seperator itself