"application/vnd.oasis.opendocument.chart",
				"application/vnd.oasis.opendocument.chart-template",
				"application/vnd.oasis.opendocument.database",
				"application/vnd.oasis.opendocument.formula",
				"application/vnd.oasis.opendocument.formula-template",
				"application/vnd.oasis.opendocument.graphics",
				"application/vnd.oasis.opendocument.graphics-template",
				"application/vnd.oasis.opendocument.image",

    @Override
    public int hashCode() {
      // Warning: this is broken if size() == 0, so it is critical that we
      // substitute an empty ImmutableSet to the user in place of this

      // It's a weird formula, but tests prove it works.
      int adjust = size() - 1;
      for (int i = 0; i < axes.size(); i++) {
        adjust *= 31;
        adjust = ~~adjust;