// ErrMaxConcurrency occurs when too many of the same named command are executed at the same time.
	ErrMaxConcurrency = CircuitError{Message: "max concurrency"}
	// ErrCircuitOpen returns when an execution attempt "short circuits". This happens due to the circuit being measured as unhealthy.
	ErrCircuitOpen = CircuitError{Message: "circuit open"}
	// ErrTimeout occurs when the provided function takes too long to execute.
	ErrTimeout = CircuitError{Message: "timeout"}