new: test token bucket declaration triggers the default init

Co-Authored-By: Lorenzo Fontana <lo@linux.com>
Signed-off-by: Leonardo Di Donato <leodidonato@gmail.com>

userspace/engine/token_bucket.h

@@ -22,8 +22,6 @@ limitations under the License.
 #include <cstdint>
 #include <functional>
 
-using token_timer = std::function<uint64_t()>;
-
 // A simple token bucket that accumulates tokens at a fixed rate and allows
 // for limited bursting in the form of "banked" tokens.
 class token_bucket
@@ -79,4 +77,4 @@ class token_bucket
     // Nanoseconds since the epoch.
     //
     uint64_t m_last_seen;
-};
+};