elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/stages/ClassExpressionQueryState.java
private QueryState markNotComputed(
			final IndexedClassExpression queryClass) {
		final QueryState state = indexed_.get(queryClass);
		if (state == null || !state.isComputed) {
			return null;
		}
		state.isComputed = false;
		if (state.node != null) {
			removeAllRelated(queryClass, state.node);
			state.node = null;
		}
		return state;
	}
private QueryState markNotComputed(
			final IndexedClassExpression queryClass) {
		final QueryState state = indexed_.get(queryClass);
		if (state == null || !state.isComputed) {
			return null;
		}
		state.isComputed = false;
		if (state.node != null) {
			removeAllRelated(queryClass, state.node);
			state.node = null;
		}
		return state;
	}
If the specified query was added to the index, this method marks it as
not-computed and deletes the query results.

@param queryClass
@return query state iff the parameter was queried, added to the index,
and the query was computed just before the call and was marked
not-computed by this call, otherwise {@code null}.