elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/stages/ClassExpressionQueryState.java
Set<? extends Node<ElkClass>> getDirectSuperClasses(
			final ElkClassExpression classExpression) throws ElkQueryException {
		final QueryState state = checkComputed(classExpression);
		if (state.node == null) {
			return null;
		} else {
			return state.node.getDirectSuperNodes();
		}
	}
Set<? extends Node<ElkClass>> getDirectSuperClasses(
			final ElkClassExpression classExpression) throws ElkQueryException {
		final QueryState state = checkComputed(classExpression);
		if (state.node == null) {
			return null;
		} else {
			return state.node.getDirectSuperNodes();
		}
	}
Returns set of {@link Node}s containing all {@link ElkClass}es that are
direct strict super-classes of the supplied class expression, if it is
satisfiable. Returns <code>null</code> otherwise. If the class expression
was not registered by {@link #registerQuery(ElkClassExpression)} or the
appropriate stage was not completed yet, throws {@link ElkQueryException}
.

@param classExpression
@return atomic direct strict super-classes of the supplied class
expression, if it is satisfiable, otherwise <code>null</code>.
@throws ElkQueryException
if the result is not ready