code: public boolean containsUserAttribute(final String _key)
          throws EFapsException
      {
          boolean ret = false;
          if (containsSessionAttribute(UserAttributesSet.CONTEXTMAPKEY)) {
              ret = ((UserAttributesSet) getSessionAttribute(UserAttributesSet.CONTEXTMAPKEY)).containsKey(_key);
          } else {
              final UserAttributesSet userAttribute = new UserAttributesSet(getPersonId());
              setSessionAttribute(UserAttributesSet.CONTEXTMAPKEY, userAttribute);
              ret = userAttribute.containsKey(_key);
          }
          return ret;
      }
docs: This method determines if UserAttribute of the Person this Context
  belongs to exists.The UserAttributes are stored in the
  {@link #sessionAttributes} Map, therefore are thought to be valid for one
  session.
  
  @param _key key to Search for
  @return true if found, else false
  
  @throws EFapsException on error