public function get_currency() {

		/**
		 * Filter the value returned for get_currency() when implemented in a specific class type
		 *
		 * @since 4.14.9
		 *
		 * @param string $currency the string representation of the value
		 * @param Abstract_Currency the object instance
		 *
		 * @return string
		 */
		$currency = apply_filters( "tec_common_value_{$this->get_value_type()}_get_currency", $this->currency, $this );

		/**
		 * Filter the value returned for get_currency() when implemented in any class
		 *
		 * @since 4.14.9
		 *
		 * @param string $currency the string representation of the value
		 * @param Abstract_Currency the object instance
		 *
		 * @return string
		 */
		return apply_filters( 'tec_common_value_get_currency', $currency, $this );
	}