@Override
  protected Coordinate getCoordinateInternal(int index) {
    return new CoordinateXY(getX(index), getY(index));
  }
Returns a coordinate sequence that translates and scales coordinates on insertion.

@param relX  x origin of the translation
@param relY  y origin of the translation
@param scale amount to scale by
@return the new empty coordinate sequence
planetiler-core/src/main/java/com/onthegomap/planetiler/geo/MutableCoordinateSequence.java