code: public EIdAccessType validateAccessType(final String accessType) {
          return typeList.get(accessType.toUpperCase(Locale.US));
      }
docs: This method checks the variable URL path after the node id resource (e.g.
  http://.../factbook/3/[ACCESSTYPE]) for the available access type to
  identify a node. The access types are defined in {@link EIdAccessType}.
  
  @param accessType
  The access type as String value encoded in the URL request.
  @return The valid access type or null otherwise.