thrift/client.go
func NewClient(ch *tchannel.Channel, serviceName string, opts *ClientOptions) TChanClient {
	client := &client{
		ch:          ch,
		sc:          ch.GetSubChannel(serviceName),
		serviceName: serviceName,
	}
	if opts != nil {
		client.opts = *opts
	}
	return client
}
func NewClient(ch *tchannel.Channel, serviceName string, opts *ClientOptions) TChanClient {
	client := &client{
		ch:          ch,
		sc:          ch.GetSubChannel(serviceName),
		serviceName: serviceName,
	}
	if opts != nil {
		client.opts = *opts
	}
	return client
}
// NewClient returns a Client that makes calls over the given tchannel to the given Hyperbahn service.