<form method="POST">
    <h3>Editing: query-pagination.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php
/**
 * Server-side rendering of the `core/query-pagination` block.
 *
 * @package WordPress
 */

/**
 * Renders the `core/query-pagination` block on the server.
 *
 * @since 5.9.0
 *
 * @param array  $attributes Block attributes.
 * @param string $content    Block default content.
 *
 * @return string Returns the wrapper for the Query pagination.
 */
function render_block_core_query_pagination( $attributes, $content ) {
	if ( empty( trim( $content ) ) ) {
		return '';
	}

	$classes            = ( isset( $attributes['style']['elements']['link']['color']['text'] ) ) ? 'has-link-color' : '';
	$wrapper_attributes = get_block_wrapper_attributes(
		array(
			'aria-label' =&gt; __( 'Pagination' ),
			'class'      =&gt; $classes,
		)
	);

	return sprintf(
		'&lt;nav %1$s&gt;%2$s&lt;/nav&gt;',
		$wrapper_attributes,
		$content
	);
}

/**
 * Registers the `core/query-pagination` block on the server.
 *
 * @since 5.8.0
 */
function register_block_core_query_pagination() {
	register_block_type_from_metadata(
		__DIR__ . '/query-pagination',
		array(
			'render_callback' =&gt; 'render_block_core_query_pagination',
		)
	);
}
add_action( 'init', 'register_block_core_query_pagination' );
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