readableIdentifier(requestShortener) {
        return `css ${requestShortener.shorten(this._identifier)}${
          this._identifierIndex ? ` (${this._identifierIndex})` : ""
        }${this.layer ? ` (layer ${this.layer})` : ""}${
          this.supports ? ` (supports ${this.supports})` : ""
        }${this.media ? ` (media ${this.media})` : ""}`;
      }
@param {Parameters<Module["readableIdentifier"]>[0]} requestShortener
@returns {ReturnType<Module["readableIdentifier"]>}