Function dds_lookup_instance 

pub unsafe extern "C" fn dds_lookup_instance(
    entity: dds_entity_t,
    data: *const c_void,
) -> dds_instance_handle_t

@brief This operation takes a sample and returns an instance handle to be used for subsequent operations. @ingroup instance_handle @component data_instance

@param[in] entity Reader or Writer entity. @param[in] data Sample with a key fields set.

@returns instance handle or DDS_HANDLE_NIL if instance could not be found from key.