code: public void set(final String _key,
                      final String _value)
          throws EFapsException
      {
          if (UserAttributesSet.MAPPER.containsKey(_key)) {
              set(_key, _value, UserAttributesSet.MAPPER.get(_key));
          } else {
              set(_key, _value, UserAttributesSet.UserAttributesDefinition.ATTRIBUTE);
          }
      }
docs: Sets a key-value pair for the attribute set of this attribute set. It
  uses {@link #set(String, String, UserAttributesDefinition)} to set the
  the relationship information. It will search in the {@link #MAPPER} to
  retrieve the definition of the attribute. If found it will use the found
  one, else it will use the a default
  {@link UserAttributesDefinition#ATTRIBUTE}.
  
  @param _key key to be set
  @param _value value to be set
  @throws EFapsException if <code>_key</code> or <code>_value</code> is
  <code>null</code>