context.go
func newIncomingContext(call IncomingCall, timeout time.Duration) (context.Context, context.CancelFunc) {
	return NewContextBuilder(timeout).
		setIncomingCall(call).
		Build()
}
func newIncomingContext(call IncomingCall, timeout time.Duration) (context.Context, context.CancelFunc) {
	return NewContextBuilder(timeout).
		setIncomingCall(call).
		Build()
}
// newIncomingContext creates a new context for an incoming call with the given span.