code: @Override
      public <T> Future<T> execute(final Callable<T> callable) {
          final Promise<T> promise = Promise();
          return execute(promise, () -> {
              try {
                  promise.success(callable.call());
              } catch (Exception ex) {
                  promise.failure(ex);
              }
          });
      }
docs: /*
  (non-Javadoc)
  
  @see com.ericsson.concurrent.Executor#execute(java.util.concurrent.Callable)