public function init_instance_settings() {
		$this->instance_settings = get_option( $this->get_instance_option_key(), null );

		// If there are no settings defined, use defaults.
		if ( ! is_array( $this->instance_settings ) ) {
			$form_fields             = $this->get_instance_form_fields();
			$this->instance_settings = array_merge( array_fill_keys( array_keys( $form_fields ), '' ), wp_list_pluck( $form_fields, 'default' ) );
		}
	}