getOutOfPlaceGroupedByParent() {
			const mOutOfPlaceGroupedByParent = {};
			for (const oOutOfPlace of Object.values(this.mPredicate2OutOfPlace)) {
				const sParentPredicate = oOutOfPlace.parentPredicate;
				const oOutOfPlaceByParent = mOutOfPlaceGroupedByParent[sParentPredicate] ??= {
					nodeFilters : [],
					nodePredicates : [],
					parentFilter : oOutOfPlace.parentFilter,
					parentPredicate : sParentPredicate
				};
				oOutOfPlaceByParent.nodeFilters.push(oOutOfPlace.nodeFilter);
				oOutOfPlaceByParent.nodePredicates.push(oOutOfPlace.nodePredicate);
			}
			return Object.values(mOutOfPlaceGroupedByParent);
		}
Returns information about the out-of-place nodes grouped by parent.

@returns {Array<{nodeFilters : string[], nodePredicates : string[], parentFilter : string?, parentPredicate : string?}>}
  A list of out-of-place nodes grouped by parent. Each entry contains all out-of-place
  nodes for a parent (root nodes if parentFilter and parentPredicate are undefined) in
  the order in which they were created.

@public