假设需要知道该read method的接口参数定义：
直接debug 进read方法，找到OModel 定义所在的js文件，拿到path /sap/ui/model/odata:
按照该路径到下述link中展开对应节点：
得到具体的参数定义：
SPath: A string containing the path to the data which should be retrieved. The path is concatenated to the sServiceUrl which was specified in the model constructor.
null:
urlParameters: A map containing the parameters that will be passed as query strings
true: asynchronous