code: function toPathExpression(operationParameters, paramsClass, path) {
    return (path || '').replace(/\{([^}]+)}/g, (_, pName) => {
      const param = operationParameters.find(p => p.paramName === pName);
      const paramName = param ? param.paramVar : pName;
      return paramsClass ?
        "${params." + paramName + "}" :
        "${" + paramName + "}";
    });
  }
docs: Returns a path expression to be evaluated, for example:
  "/a/{var1}/b/{var2}/" returns "/a/${params.var1}/b/${params.var2}"
  if there is a parameters class, or "/a/${var1}/b/${var2}" otherwise.