question: private void appendCoordinate ( CoordinateSequence seq , int i , Writer writer ) throws IOException { writer . write ( writeNumber ( seq . getX ( i ) ) + " " + writeNumber ( seq . getY ( i ) ) ) ; if ( outputDimension >= 3 && seq . getDimension ( ) >= 3 ) { double z = seq . getOrdinate ( i , 3 ) ; if ( ! Double . isNaN ( z ) ) { writer . write ( " " ) ; writer . write ( writeNumber ( z ) ) ; } } }
target:  Appends the i'th coordinate from the sequence to the writer