Optional request headers.
Object, default = {}
Adding properties to
.httpHeaders object will instruct the grid to submit these parameters to the remote data source
with each remote request (pull, sort, search, save, delete).
This is similar to the
.postData object, however the
.httpHeaders object will be used
for the AJAX header part, not for the data part.
You can defined it during object creation:
Or any time during the run-time: