public static function save_fields( $options, $data = null ) {
			if ( is_null( $data ) ) {
				$data = $_POST; // WPCS: input var okay, CSRF ok.
			}
			if ( empty( $data ) ) {
				return false;
			}

			// Options to update will be stored here and saved later.
			$update_options   = array();
			$autoload_options = array();

			// Loop options and get values to save.
			foreach ( $options as $option ) {
				if ( ! isset( $option['id'] ) || ! isset( $option['type'] ) || ( isset( $option['is_option'] ) && false === $option['is_option'] ) ) {
					continue;
				}

				// Get posted value.
				if ( strstr( $option['id'], '[' ) ) {
					parse_str( $option['id'], $option_name_array );
					$option_name  = current( array_keys( $option_name_array ) );
					$setting_name = key( $option_name_array[ $option_name ] );
					$raw_value    = isset( $data[ $option_name ][ $setting_name ] ) ? wp_unslash( $data[ $option_name ][ $setting_name ] ) : null;
				} else {
					$option_name  = $option['id'];
					$setting_name = '';
					$raw_value    = isset( $data[ $option['id'] ] ) ? wp_unslash( $data[ $option['id'] ] ) : null;
				}

				// Format the value based on option type.
				switch ( $option['type'] ) {
					case 'checkbox':
						$value = '1' === $raw_value || 'yes' === $raw_value ? 'yes' : 'no';
						break;
					case 'textarea':
						$value = wp_kses_post( trim( $raw_value ) );
						break;
					case 'multiselect':
					case 'multi_select_countries':
						$value = array_filter( array_map( 'wc_clean', (array) $raw_value ) );
						break;
					case 'image_width':
						$value = array();
						if ( isset( $raw_value['width'] ) ) {
							$value['width']  = wc_clean( $raw_value['width'] );
							$value['height'] = wc_clean( $raw_value['height'] );
							$value['crop']   = isset( $raw_value['crop'] ) ? 1 : 0;
						} else {
							$value['width']  = $option['default']['width'];
							$value['height'] = $option['default']['height'];
							$value['crop']   = $option['default']['crop'];
						}
						break;
					case 'select':
						$allowed_values = empty( $option['options'] ) ? array() : array_map( 'strval', array_keys( $option['options'] ) );
						if ( empty( $option['default'] ) && empty( $allowed_values ) ) {
							$value = null;
							break;
						}
						$default = ( empty( $option['default'] ) ? $allowed_values[0] : $option['default'] );
						$value   = in_array( $raw_value, $allowed_values, true ) ? $raw_value : $default;
						break;
					case 'relative_date_selector':
						$value = wc_parse_relative_date_option( $raw_value );
						break;
					default:
						$value = wc_clean( $raw_value );
						break;
				}

				/**
				 * Fire an action when a certain 'type' of field is being saved.
				 *
				 * @deprecated 2.4.0 - doesn't allow manipulation of values!
				 */
				if ( has_action( 'woocommerce_update_option_' . sanitize_title( $option['type'] ) ) ) {
					wc_deprecated_function( 'The woocommerce_update_option_X action', '2.4.0', 'woocommerce_admin_settings_sanitize_option filter' );
					do_action( 'woocommerce_update_option_' . sanitize_title( $option['type'] ), $option );
					continue;
				}

				/**
				 * Sanitize the value of an option.
				 *
				 * @since 2.4.0
				 */
				$value = apply_filters( 'woocommerce_admin_settings_sanitize_option', $value, $option, $raw_value );

				/**
				 * Sanitize the value of an option by option name.
				 *
				 * @since 2.4.0
				 */
				$value = apply_filters( "woocommerce_admin_settings_sanitize_option_$option_name", $value, $option, $raw_value );

				if ( is_null( $value ) ) {
					continue;
				}

				// Check if option is an array and handle that differently to single values.
				if ( $option_name && $setting_name ) {
					if ( ! isset( $update_options[ $option_name ] ) ) {
						$update_options[ $option_name ] = get_option( $option_name, array() );
					}
					if ( ! is_array( $update_options[ $option_name ] ) ) {
						$update_options[ $option_name ] = array();
					}
					$update_options[ $option_name ][ $setting_name ] = $value;
				} else {
					$update_options[ $option_name ] = $value;
				}

				$autoload_options[ $option_name ] = isset( $option['autoload'] ) ? (bool) $option['autoload'] : true;

				/**
				 * Fire an action before saved.
				 *
				 * @deprecated 2.4.0 - doesn't allow manipulation of values!
				 */
				do_action( 'woocommerce_update_option', $option );
			}

			// Save all options in our array.
			foreach ( $update_options as $name => $value ) {
				update_option( $name, $value, $autoload_options[ $name ] ? 'yes' : 'no' );
			}

			return true;
		}