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;
	}
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;
	}
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 ; }
Aync loading of attachment images

@param array $atts
@param WP_Post $attachment
@param string|array $size
@return array
Aync loading of attachment images