code: @Deprecated
      public DateMidnight toDateMidnight(DateTimeZone zone) {
          zone = DateTimeUtils.getZone(zone);
          Chronology chrono = getChronology().withZone(zone);
          return new DateMidnight(getYear(), getMonthOfYear(), getDayOfMonth(), chrono);
      }
docs: Converts this LocalDate to a DateMidnight.
  <p>
  As from v1.5, you are recommended to avoid DateMidnight and use
  {@link #toDateTimeAtStartOfDay()} instead because of the exception
  detailed below.
  <p>
  This method will throw an exception if the time zone switches
  to Daylight Savings Time at midnight and this LocalDate represents
  that switchover date. The problem is that there is no such time as
  midnight on the required date, and as such an exception is thrown.
  <p>
  This instance is immutable and unaffected by this method call.
  
  @param zone  the zone to get the DateMidnight in, null means default zone
  @return the DateMidnight instance
  @deprecated DateMidnight is deprecated