code: public void writeDouble(double value)
          throws IOException
      {
          long bits = Double.doubleToLongBits(value);
  
          os.write('D');
          os.write((byte) (bits >> 56));
          os.write((byte) (bits >> 48));
          os.write((byte) (bits >> 40));
          os.write((byte) (bits >> 32));
          os.write((byte) (bits >> 24));
          os.write((byte) (bits >> 16));
          os.write((byte) (bits >> 8));
          os.write((byte) (bits));
      }
docs: Writes a double value to the stream.  The double will be written
  with the following syntax:
  
  <code><pre>
  D b64 b56 b48 b40 b32 b24 b16 b8
  </pre></code>
  
  @param value the double value to write.