public void moveEntitiesTo(IGroup dest) {
		checkGroup();
		if (dest.isGroup() == false) {
			throw new UnsupportedOperationException();
		}
		for (ILeaf ent : getLeafsDirect()) {
			((EntityImpl) ent).parentContainer = dest;
		}
		for (IGroup g : dest.getChildren()) {
			// ((EntityImpl) g).parentContainer = dest;
			throw new IllegalStateException();
		}

		for (IGroup g : getChildren()) {
			if (g == dest) {
				continue;
			}
			((EntityImpl) g).parentContainer = dest;
		}

	}