getList() response Json object loss some data

[RobinsonSir]

The data in server:
[{"id":1,"name":"myName1","head":"6E02"},{"id":2,"name":"myName2","head":"6E03"}]
when I use getList()，I get something like this: [{"id":1,"name":"myName1","route":"dtTypeList","reqParams":null,"restangularized":true,"fromServer":true,"parentResource":null,"restangularCollection":false},{"id":2,"name":"myName2","route":"dtTypeList","reqParams":null,"restangularized":true,"fromServer":true,"parentResource":null,"restangularCollection":false}]
It loss 'head' property data.
I don't know how to fix this problem.

restangular v1.6.1 & AngularJS v1.6.7