@Override
    public void startProvisioningWithOutputOOB(@NonNull final UnprovisionedMeshNode unprovisionedMeshNode,
                                               @NonNull final OutputOOBAction oobAction) throws IllegalArgumentException {
        if (isAddressValid(unprovisionedMeshNode)) {
            mMeshProvisioningHandler.startProvisioningWithOutputOOB(unprovisionedMeshNode, oobAction);
        }
    }
Appends the PDUs that are segmented at gatt layer.

@param mtuSize mtu size supported by the device/node
@param pdu     pdu received by the provisioner
@return the combine pdu or returns null if not complete.
mesh/src/main/java/no/nordicsemi/android/mesh/MeshManagerApi.java