code: protected void loadOptionalExecutor(final String executorBinder) {
          try {
              final Method bindExecutor = RepositoryModule.class.getDeclaredMethod("bindExecutor", Class.class);
              bindExecutor.setAccessible(true);
              try {
                  Class.forName(executorBinder)
                          .getConstructor(RepositoryModule.class, Method.class)
                          .newInstance(this, bindExecutor);
              } finally {
                  bindExecutor.setAccessible(false);
              }
          } catch (Exception ignore) {
              if (logger.isTraceEnabled()) {
                  logger.trace("Failed to process executor loader " + executorBinder, ignore);
              }
          }
      }
docs: Allows to load executor only if required jars are in classpath.
  For example, no need for graph dependencies if only object db is used.
  
  @param executorBinder executor binder class
  @see ru.vyarus.guice.persist.orient.support.repository.ObjectExecutorBinder as example