WP_REST_Posts_Controller::get_post( int $id )

	protected function get_post( $id ) {
		$error = new WP_Error( 'rest_post_invalid_id', __( 'Invalid post ID.' ), array( 'status' => 404 ) );
		if ( (int) $id <= 0 ) {
			return $error;
		}

		$post = get_post( (int) $id );
		if ( empty( $post ) || empty( $post->ID ) || $this->post_type !== $post->post_type ) {
			return $error;
		}

		return $post;
	}