// Check that no relation has multiple sources of data connected to it.
// FIXME: This only detects the error at this level of the hierarchy.
// Probably need to recursively descend into composite actors.
CompositeEntity container = (CompositeEntity) getContainer();
Iterator relations = container.relationList().iterator();
while (relations.hasNext()) {
IORelation relation = (IORelation) relations.next();
if (relation.linkedSourcePortList().size() > 1) {