in v2/processor.go [115:124]
func NewProcessor(receiver Receiver, handler HandlerFunc, options *ProcessorOptions) *Processor {
opts := applyProcessorOptions(options)
receiverEx := NewReceiverEx("receiver", receiver)
return &Processor{
receivers: map[string]*ReceiverEx{receiverEx.name: receiverEx},
handle: handler,
options: *opts,
concurrencyTokens: make(chan struct{}, opts.MaxConcurrency),
}
}