Forwards 'error' events from a connection to its owning emitter, but only
when a consumer is listening. Emitting 'error' on an EventEmitter with no
listeners throws, which would turn a transient connection error (e.g. a
failed init handshake before the consumer attached its listener) into an
unhandled rejection.
Parameters
emitter: EventEmitter
The owner emitter (Queue, Worker, FlowProducer, ...).
connection: EventEmitter
The connection whose 'error' events should be forwarded.
Forwards 'error' events from a connection to its owning emitter, but only when a consumer is listening. Emitting 'error' on an EventEmitter with no listeners throws, which would turn a transient connection error (e.g. a failed init handshake before the consumer attached its listener) into an unhandled rejection.