       uint_to_buffer(16, flatsp.length),
       flatsp
     ]
+    console.log "prepare payload ->"
+    console.log flatsp.toString('hex')
 
     trailer = Buffer.concat [
       new Buffer([ C.versions.signature.V4, 0xff ]),

    hashed_subpacket_count = @slice.read_uint16()
    end = @slice.i + hashed_subpacket_count
    o.sig_data = @slice.peek_to_buffer hashed_subpacket_count
    o.hashed_subpackets = (@parse_subpacket() while @slice.i < end)
    unhashed_subpacket_count = @slice.read_uint16()
    end = @slice.i + unhashed_subpacket_count

  to_buffer : () ->
    inner = @_v_to_buffer()
    Buffer.concat [
      encode_length(inner.length + 1),
      uint_to_buffer(8, @type),
      inner
    ]
