def from_json(s):
    """Given a JSON-encoded string s, build a message object.

    """
    d = json.loads(s)
    sbp = SBP.from_json_dict(d)
    return MsgEphemerisOld(sbp)

  def from_json(s):
    """Given a JSON-encoded string s, build a message object.

    """
    d = json.loads(s)
    sbp = SBP.from_json_dict(d)
    return MsgBaselineNED(sbp)

  def from_json(data):
    """Given a JSON-encoded message, build an object.

    """
    d = json.loads(data)
    sbp = SBP.from_json_dict(d)
    return MsgIarState(sbp)

  def from_json(s):
    """Given a JSON-encoded string s, build a message object.

    """
    d = json.loads(s)
    sbp = SBP.from_json_dict(d)
    return MsgFileioReadDir(sbp)

  def from_json(s):
    """Given a JSON-encoded string s, build a message object.

    """
    d = json.loads(s)
    sbp = SBP.from_json_dict(d)
    return MsgStmFlashUnlockSector(sbp)

  def from_json(s):
    """Given a JSON-encoded string s, build a message object.

    """
    d = json.loads(s)
    sbp = SBP.from_json_dict(d)
    return MsgSettingsReadByIndex(sbp)

def assert_package(test_filename, pkg_name):
  """
  Runs unit tests for message bindings by reading a YAML unit test
  specification, parsing a raw packet for each test, and then
  asserting that SBP messages and parsed payloads have their intended
  values.

  Parameters
  ----------
  test_filename : str
    Filepath to unit test specifications
  pkg_name : str
    Name of package to test

  """
  with open(test_filename, 'r') as f:
    pkg = yaml.load(f.read())
    _assert_sane_package(pkg_name, pkg)
    for test_case in pkg['tests']:
      sbp = SBP.unpack(base64.standard_b64decode(test_case['raw_packet']))
      _assert_sbp(sbp, test_case['sbp'])
      _assert_msg(dispatch(sbp), test_case['msg'])
      _assert_msg_roundtrip(dispatch(sbp), test_case['raw_packet'])
      _assert_msg_roundtrip_json(dispatch(sbp), test_case['raw_json'])
      _assert_materialization(test_case['msg'], sbp, test_case['raw_json'])

  def from_json(data):
    """Given a JSON-encoded message, build an object.

    """
    d = json.loads(data)
    sbp = SBP.from_json_dict(d)
    return MsgBootloaderHandshake(sbp)

  def from_json(data):
    """Given a JSON-encoded message, build an object.

    """
    d = json.loads(data)
    sbp = SBP.from_json_dict(d)
    return MsgM25FlashWriteStatus(sbp)

  def from_json(data):
    """Given a JSON-encoded message, build an object.

    """
    d = json.loads(data)
    sbp = SBP.from_json_dict(d)
    return MsgSettingsReadByIndex(sbp)

  def from_json(s):
    """Given a JSON-encoded string s, build a message object.

    """
    d = json.loads(s)
    sbp = SBP.from_json_dict(d)
    return MsgBootloaderHandshake(sbp)