Hello:
  empty:
    message: {}
    expectation: false
    description: empty (invalid) message
  hello:
    message:
      header:
        version: 1
        type: OFPT_HELLO
        length: 8
        xid: 0
    expectation: true
    description: plain Hello message
  helloLowVer:
    message:
      header:
        version: 0
        type: OFPT_HELLO
        length: 8
        xid: 0
    expectation: false
    description: wrong version (low)
  helloHighVer:
    message:
      header:
        version: 256
        type: OFPT_HELLO
        length: 8
        xid: 0
    expectation: false
    description: wrong version (high)