code: public Packet putDouble(double d, ByteOrder order) {
          return putLong(Double.doubleToRawLongBits(d), order);
      }
docs: Writes a single {@code double} with the specified {@link ByteOrder} to this {@link Packet}'s payload.
  
  @param d     A {@code double}.
  @param order The internal byte order of the {@code double}.
  @return The {@link Packet} to allow for chained writes.
  @see #putLong(long, ByteOrder)