Using the Stdout stream and NullEncoder yields errors

There seems to be an error when using the stdout stream as such:

Error sending message (TypeError('expected a character buffer object',)): [uuid: "\014\336\030\360F\\_\263\233\373\376\000\353\331\337E"
timestamp: 1398981216141190144
type: "timer"
logger: "onyx-dev"
severity: 4
payload: "1"
env_version: "0.8"
pid: 43833
hostname: "quanta.local"
fields {
  name: "rate"
  value_type: DOUBLE
  representation: ""
  value_double: 1.0
}
fields {
  name: "name"
  value_type: STRING
  representation: ""
  value_string: "newtab_serving"
}
]

mozilla-services / heka-py

Using the Stdout stream and NullEncoder yields errors #23