code: private DOMAccess checkProjectionInstance(final Object projection) {
          if (java.lang.reflect.Proxy.isProxyClass(projection.getClass())) {
              InvocationHandler invocationHandler = java.lang.reflect.Proxy.getInvocationHandler(projection);
              if (invocationHandler instanceof ProjectionInvocationHandler) {
                  if (projection instanceof DOMAccess) {
                      return (DOMAccess) projection;
                  }
              }
          }
          throw new IllegalArgumentException("Given object " + projection + " is not a projection.");
      }
docs: Ensures that the given object is a projection created by a projector.
  
  @param projection
  @return