@RestrictTo(RestrictTo.Scope.LIBRARY)
    void setAddedAppKeyIndex(final int index) {
        if (!MeshParserUtils.isNodeKeyExists(mAddedAppKeys, index)) {
            this.mAddedAppKeys.add(new NodeKey(index));
        }
    }
Adds an AppKey index that was added to the node

@param index AppKey index
mesh/src/main/java/no/nordicsemi/android/mesh/transport/ProvisionedMeshNode.java