code: public Geometry getGeometry(Object objectToGet) throws InvalidObjectReaderException {
          if (objectToGet == null) {
              throw new IllegalArgumentException("The given object may not be null");
          }
          if (objectToGet.getClass() != entityClass) {
              throw new InvalidObjectReaderException("Class of target object does not correspond with entityclass of this reader.");
          }
          if (geometryAccessor == null) {
              return null;
          } else {
              return (Geometry) geometryAccessor.getValueFrom(objectToGet);
          }
      }
docs: Will retrieve the value of the geometryfield in the given object. If no geometryfield
  exists, null is returned. If more than one exist, a random one is returned.
  
  @param objectToGet the object from which the geometry is to be fetched.
  @return the geometry of the given object
  @throws InvalidObjectReaderException If the class of objectToGet does not correspond with the entityclass of this reader.
  @throws IllegalArgumentException     the given object may not be null