code: public void set(final String _key,
                      final String _value,
                      final UserAttributesDefinition _definition)
          throws EFapsException
      {
          if (_key == null || _value == null) {
              throw new EFapsException(this.getClass(), "set", _key, _value, _definition);
          } else {
              final UserAttribute userattribute = this.attributes.get(_key);
              if (userattribute == null) {
                  this.attributes.put(_key, new UserAttribute(_definition.name, _value.trim(), true));
              } else if (!userattribute.getValue().equals(_value.trim())) {
                  userattribute.setUpdate(true);
                  userattribute.setValue(_value.trim());
              }
          }
      }
docs: Sets a key-value pair into the attribute set of an user. The method will
  search for the key and if the key already exists it will update the user
  attribute in this set. If the key does not exist a new user attribute
  will be added to this set.
  
  @param _key key to be set
  @param _value value to be set
  @param _definition type of the key-value pair
  @throws EFapsException if <code>_key</code> or <code>_value</code> is
  <code>null</code>