public function createIdentifier($data)
	{
		// Get the data ready for creation.
		switch(gettype($data))
		{
			// Use an Object to update.
			case 'object':
				// Add entity type and key to creation data.
				$createData = ['entity_type' => $data->getType(), 'entity_id' => $data->getKey()];
			break;

			default:
				$createData = $data;
			break;
		}

		// Create the newly created entity's EntityIdentifier.
		return $this->aggregate[IdentifierServiceProvider::getProviderKey()]->create($createData);
	}