Hook example

/**
 * Add wrapper to single event content
 */
function customname_event_before_single_content() {
	echo '<div class="thumbnail">';
	the_post_thumbnail();
	echo '</div>';

	echo '<div class="event-content-wrapper">';
}
add_action( 'twstudio_event_before_single_content', 'customname_event_before_single_content', 55 );

function customname_event_after_single_content() {
	echo '</div>';
}
add_action( 'twstudio_event_after_single_content', 'customname_event_after_single_content', 5 );

Another ONE:

/**
 * Adds wrapper around single product image and main product data
 */
function twstudio_single_product_wrapper_before() {
   echo '<div class="single-product-container">';
}
add_action( 'woocommerce_before_single_product_summary', 'twstudio_single_product_wrapper_before', 5 );


function twstudio_single_product_wrapper_after() {
   echo '</div>';
}
add_action( 'woocommerce_after_single_product_summary', 'twstudio_single_product_wrapper_after', 5 );