docs: static String preambleToString(final Memory mem) {
      final int preLongs = getAndCheckPreLongs(mem);  // make sure we can get the assumed preamble
  
      final Family family = Family.idToFamily(mem.getByte(FAMILY_BYTE));
  
      switch (family) {
        case RESERVOIR:
        case VAROPT:
          return sketchPreambleToString(mem, family, preLongs);
        case RESERVOIR_UNION:
        case VAROPT_UNION:
          return unionPreambleToString(mem, family, preLongs);
        default:
          throw new SketchesArgumentException("Inspecting preamble with Sampling family's "
                  + "PreambleUtil with object of family " + family.getFamilyName());
      }
    }