wp-includes/customize/class-wp-widget-area-customize-control.php:40Refreshes the parameters passed to the JavaScript via JSON.
public function to_json() { parent::to_json(); $exported_properties = array( 'sidebar_id' ); foreach ( $exported_properties as $key ) { $this->json[ $key ] = $this->$key; } }Introduced in 3.9.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/customize/class-wp-widget-area-customize-control.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.