/*D
   MPI_T_event_get_timestamp - Returns the timestamp of when the event was initially observed by the implementation

Synopsis:
.vb
int MPI_T_event_get_timestamp(MPI_T_event_instance event_instance,
                              MPI_Count *event_timestamp)
.ve

Input Parameters:
. event_instance - event instance provided to the callback function (handle)

Output Parameters:
. event_timestamp - timestamp the event was observed (integer)

.N ThreadSafe

.N Errors
.N MPI_SUCCESS
.N MPI_T_ERR_INVALID
.N MPI_T_ERR_INVALID_HANDLE
.N MPI_T_ERR_NOT_INITIALIZED
.N MPI_ERR_OTHER

D*/

