code: public final TimestampType getTimestampAsTimestamp(int columnIndex) {
          final long timestamp = getTimestampAsLong(columnIndex);
          if (m_wasNull) return null;
          return new TimestampType(timestamp);
      }
docs: Retrieve the {@link org.voltdb.types.TimestampType TimestampType}
  value stored in the column specified by index.
  Note that VoltDB uses GMT universally within its process space. Date objects sent over
  the wire from clients may seem to be different times because of this, but it is just
  a time zone offset.
  @param columnIndex Index of the column
  @return {@link org.voltdb.types.TimestampType TimestampType}
  value stored in the specified column
  @see #wasNull()