code: @Deprecated
      public static BigDecimal toBigDecimalTrunc(BigDecimal universalTime, int timeScale)
      {
          TimeScaleData data = getTimeScaleData(timeScale);
          BigDecimal units = new BigDecimal(data.units);
          BigDecimal epochOffset = new BigDecimal(data.epochOffset);
          
          return universalTime.divide(units, BigDecimal.ROUND_DOWN).subtract(epochOffset);
      }
docs: Convert a time in the Universal Time Scale into another time
  scale. The division used to do the conversion rounds down.
  
  NOTE: This is an internal routine used by the tool that
  generates the to and from limits. Use it at your own risk.
  
  @param universalTime the time in the Universal Time scale
  @param timeScale the time scale to convert to
  @return the time in the given time scale
  
  @deprecated This API is ICU internal only.
  @hide draft / provisional / internal are hidden on Android