code: public Coordinate getCoordinate(Geometry geometry) {
  		LineString lineString = getLineString(geometry);
  		if (lineString != null && coordinateIndex >= 0) {
  			return lineString.getCoordinateN(coordinateIndex);
  		}
  		return null;
  	}
docs: Returns the coordinate that is described by this index (if there is one).
  
  @param geometry
  The geometry to search in.
  @return Returns the coordinate or null.