protected LinearRing canBuildExteriorPolygon(Polygon polygon) throws ParserException {
    AbstractRingProperty ringProperty = polygon.getExteriorValue();
    AbstractRing ring = ringProperty.getAbstractRing();

    return ((ring != null) && (ring instanceof org.geosdi.geoplatform.gml.api.LinearRing))
        ? linearRingParser.parseGeometry((org.geosdi.geoplatform.gml.api.LinearRing) ring)
        : null;
  }
  protected LinearRing[] canBuildInteriorPolygon(Polygon polygon) throws ParserException {
    List<LinearRing> interiorElements =
        new ArrayList<LinearRing>(polygon.getInteriorValues().size());

    for (AbstractRingProperty ringProperty : polygon.getInteriorValues()) {
      AbstractRing ring = ringProperty.getAbstractRing();
      if ((ring != null) && (ring instanceof LinearRing)) {
        interiorElements.add(
            this.linearRingParser.parseGeometry((org.geosdi.geoplatform.gml.api.LinearRing) ring));
      }
    }

    return interiorElements.toArray(new LinearRing[interiorElements.size()]);
  }