key from ListSchemaNode has different revision

example in snippet:

ListSchemaNode groupList;
Qname keyGroupId = groupList.keyDefinition().get(0)
groupList.getDataChildByName(keyGroupId) returns null

because

keyGroupId has revision=2013-10-18
child representing key in groupList has revision=2013-08-19

keyGroupId.toString:
(urn:opendaylight:group:types?revision=2013-10-18)group-id

part of groupList.childNodes.toString:
(urn:opendaylight:flow:inventory?revision=2013-08-19)group-id=LeafSchemaNodeImpl[qname=(urn:opendaylight:flow:inventory?revision=2013-08-19)group-id, path=SchemaPath [path=[(urn:opendaylight:inventory?revision=2013-08-19)nodes, (urn:opendaylight:inventory?revision=2013-08-19)node, (urn:opendaylight:flow:inventory?revision=2013-08-19)group, (urn:opendaylight:flow:inventory?revision=2013-08-19)group-id], absolute=true]]

Yang modules in attachment