Source

File: wp-admin/includes/class-wp-list-table.php

protected function bulk_actions( $which = '' ) {
		if ( is_null( $this->_actions ) ) {
			$this->_actions = $this->get_bulk_actions();

			/**
			 * Filters the list table bulk actions drop-down.
			 *
			 * The dynamic portion of the hook name, `$this->screen->id`, refers
			 * to the ID of the current screen, usually a string.
			 *
			 * @since 3.1.0
			 *
			 * @param string[] $actions An array of the available bulk actions.
			 */
			$this->_actions = apply_filters( "bulk_actions-{$this->screen->id}", $this->_actions ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores

			$two = '';
		} else {
			$two = '2';
		}

		if ( empty( $this->_actions ) ) {
			return;
		}

		echo '<label for="bulk-action-selector-' . esc_attr( $which ) . '" class="screen-reader-text">' . __( 'Select bulk action' ) . '</label>';
		echo '<select name="action' . $two . '" id="bulk-action-selector-' . esc_attr( $which ) . "\">\n";
		echo '<option value="-1">' . __( 'Bulk actions' ) . "</option>\n";

		foreach ( $this->_actions as $name => $title ) {
			$class = 'edit' === $name ? ' class="hide-if-no-js"' : '';

			echo "\t" . '<option value="' . $name . '"' . $class . '>' . $title . "</option>\n";
		}

		echo "</select>\n";

		submit_button( __( 'Apply' ), 'action', '', false, array( 'id' => "doaction$two" ) );
		echo "\n";
	}