If read(byte[] buf, int offset, int len) is invoked on a StateInputStream, we do the following:

• stateQueue.take() is called to grab the next message (block if no message is available)
• Then we return the byte[] buffer of the message. The number of bytes returned is buffer.length, not len !
  This has 3 issues:
  #1 It violates the contract of read(): if we wanted to read len bytes at most, we cannot get more bytes back. E.g. if we wanted to read 500 bytes, but get 1000 back, then that's incorrect
  #2 If we allocate a buffer of 500 bytes, but the next message has 1000 bytes, we will get an array out of bounds exception
  #3 Even if this was correct, if we wanted to read 500 bytes, but the next message has 1000 bytes, we'd only read 500 bytes and throw the remainder away !