code: static long getHiFieldOffset(final Format format, final HiField hiField) {
      final int formatIdx = format.ordinal();
      final int hiFieldIdx = hiField.ordinal();
      final long fieldOffset = hiFieldOffset[formatIdx][hiFieldIdx] & 0xFF; //initially a byte
      if (fieldOffset == 0) {
        throw new SketchesStateException("Undefined preamble field given the Format: "
            + "Format: " + format.toString() + ", HiField: " + hiField.toString());
      }
      return fieldOffset;
    }
docs: Returns the defined byte offset from the start of the preamble given the <i>HiField</i>
  and the <i>Format</i>.
  Note this can not be used to obtain the stream offsets.
  @param format the desired <i>Format</i>
  @param hiField the desired preamble <i>HiField</i> after the first eight bytes.
  @return the defined byte offset from the start of the preamble for the given <i>HiField</i>
  and the <i>Format</i>.