public function format_string( $string ) {
		$find    = array_keys( $this->placeholders );
		$replace = array_values( $this->placeholders );

		// If using legacy find replace, add those to our find/replace arrays first. @todo deprecate in 4.0.0.
		$find    = array_merge( (array) $this->find, $find );
		$replace = array_merge( (array) $this->replace, $replace );

		// Take care of blogname which is no longer defined as a valid placeholder.
		$find[]    = '{blogname}';
		$replace[] = $this->get_blogname();

		// If using the older style filters for find and replace, ensure the array is associative and then pass through filters. @todo deprecate in 4.0.0.
		if ( has_filter( 'woocommerce_email_format_string_replace' ) || has_filter( 'woocommerce_email_format_string_find' ) ) {
			$legacy_find    = $this->find;
			$legacy_replace = $this->replace;

			foreach ( $this->placeholders as $find => $replace ) {
				$legacy_key                    = sanitize_title( str_replace( '_', '-', trim( $find, '{}' ) ) );
				$legacy_find[ $legacy_key ]    = $find;
				$legacy_replace[ $legacy_key ] = $replace;
			}

			$string = str_replace( apply_filters( 'woocommerce_email_format_string_find', $legacy_find, $this ), apply_filters( 'woocommerce_email_format_string_replace', $legacy_replace, $this ), $string );
		}

		/**
		 * Filter for main find/replace.
		 *
		 * @since 3.2.0
		 */
		return apply_filters( 'woocommerce_email_format_string', str_replace( $find, $replace, $string ), $this );
	}