public function get_value() {
		$config = $this->options->get( $this->options_key );
		$value  = $config[ $this->id ];

		// Make sure $value is in $option_values if $option_values is set.
		if ( isset( $this->option_values ) && ! isset( $this->option_values[ $value ] ) ) {
			$value = null;
		}

		return $value;
	}