code: protected static UUID extractUUID(AttributeProvider provider) {
  		AttributeValue value;
  
  		value = provider.getAttribute(UUID_ATTR);
  		if (value != null) {
  			try {
  				return value.getUUID();
  			} catch (InvalidAttributeTypeException e) {
  				//
  			} catch (AttributeNotInitializedException e) {
  				//
  			}
  		}
  
  		value = provider.getAttribute(ID_ATTR);
  		if (value != null) {
  			try {
  				return value.getUUID();
  			} catch (InvalidAttributeTypeException e) {
  				//
  			} catch (AttributeNotInitializedException e) {
  				//
  			}
  		}
  
  		return null;
  	}
docs: Extract the UUID from the attributes.
  
  @param provider is a provider of attributes
  @return the uuid if found or <code>null</code> if none.