code: public void setUserAttribute(String key, Object newValue)
      {
          Object oldValue = userAttributes.put(key, newValue);
          propertyChangeSupport.firePropertyChange(key, oldValue, newValue);
          propertyChangeSupport.firePropertyChange(USER_ATTRIBUTES, null, userAttributes);
      }
docs: Add a key/value pair to the user attributes map.
  
  @param key
  a unique string code.
  @param newValue
  the associated value.