public function _async_attachment_images( $atts, $attachment, $size ) {
		if ( ! $this->_is_async_attachment_images() ) {
			return $atts;
		}

		$atts['data-src'] = $atts['src'];
		$atts['src']      = wp_get_attachment_image_url( $attachment->ID, 'wppso-minimum-thumbnail' );

		if ( isset( $atts['srcset'] ) ) {
			$atts['data-srcset'] = $atts['srcset'];
			$atts['srcset']      = null;
		}

		$atts['decoding'] = 'async';
		return $atts;
	}