mock gps provider

can traccar client make use of mock gps provider?

Yes, from apps point of view it's just a regular GPS provider.

i thought so too , but when i turn off my device gps(internal gps provider) and enable mock gps provider (to use external gps provider) ...the traccar client aplication stops sending any location updates to server

do i need to change to insert this code ??

http://android.xsoftlab.net/training/location/location-testing.html

The link is for sending mock location. For receiving you don't need anything, as far as I know.