code: @SafeVarargs
      public final ContinuableFuture<Boolean> asyncExists(final String query, final Object... parameters) {
          return asyncExecutor.execute(new Callable<Boolean>() {
              @Override
              public Boolean call() throws Exception {
                  return exists(query, parameters);
              }
          });
      }
docs: Always remember to set "<code>LIMIT 1</code>" in the sql statement for better performance.
  
  @param query
  @param parameters
  @return