code: @Nonnull
    public <T extends IValidationExecutorSet> T registerValidationExecutorSet (@Nonnull final T aVES)
    {
      ValueEnforcer.notNull (aVES, "VES");
  
      final VESID aKey = aVES.getID ();
      m_aRWLock.writeLocked ( () -> {
        if (m_aMap.containsKey (aKey))
          throw new IllegalStateException ("Another validation executor set with the ID '" +
                                           aKey +
                                           "' is already registered!");
        m_aMap.put (aKey, aVES);
      });
      return aVES;
    }
docs: Register a validation executor set into this registry.
  
  @param aVES
  The object to register. MAy not be <code>null</code>.
  @return The passed parameter
  @throws IllegalStateException
  If another object with the same ID is already registered in this
  registry.
  @param <T>
  The {@link IValidationExecutorSet} implementation that is added and
  returned.