code: @Nonnull
      public static IRI create(@Nonnull String str) {
          checkNotNull(str, "str cannot be null");
          int index = XMLUtils.getNCNameSuffixIndex(str);
          if (index < 0) {
              // no ncname
              return new IRI(str, "");
          }
          return new IRI(str.substring(0, index), str.substring(index));
      }
docs: Creates an IRI from the specified String.
  
  @param str The String that specifies the IRI
  @return The IRI that has the specified string representation.