code: @Override
      public void lock(final Object maintainer) throws CouldNotPerformException {
          synchronized (maintainerLock) {
              if (this.maintainer != null) {
                  throw new CouldNotPerformException("Could not lock remote because it is already locked by another instance!");
              }
              this.maintainer = maintainer;
          }
      }
docs: {@inheritDoc}
  
  @throws CouldNotPerformException {@inheritDoc}