public function update_item( $request ) {

		$object = $this->get_object( $request['id'] );
		if ( is_wp_error( $object ) ) {
			return $object;
		}

		// Ensure we're not trying to update the email to an email that already exists.
		$owner_id = email_exists( $request['email'] );

		if ( $owner_id && $owner_id !== $request['id'] ) {
			return llms_rest_bad_request_error( __( 'Invalid email address.', 'lifterlms' ) );
		}

		// Cannot change a username.
		if ( ! empty( $request['username'] ) && $request['username'] !== $object->get( 'user_login' ) ) {
			return llms_rest_bad_request_error( __( 'Username is not editable.', 'lifterlms' ) );
		}

		return parent::update_item( $request );

	}