func NewClient(addr, transport string, mustConnect bool) (client Client, err error) {
	switch transport {
	case "socket":
		client = NewSocketClient(addr, mustConnect)
	case "grpc":
		client = NewGRPCClient(addr, mustConnect)
	default:
		err = fmt.Errorf("unknown abci transport %s", transport)
	}
	return
}
----------------------------------------
NewClient returns a new ABCI client of the specified transport type.
It returns an error if the transport is not "socket" or "grpc"
package abcicli
import (
	"fmt"
	"sync"
	"github.com/line/ostracon/abci/types"
	"github.com/line/ostracon/libs/service"
	tmsync "github.com/line/ostracon/libs/sync"
)
const (
	dialRetryIntervalSeconds = 3
	echoRetryIntervalSeconds = 1
)
type Client interface {
	service.Service
	SetGlobalCallback(GlobalCallback)
	GetGlobalCallback() GlobalCallback
	Error() error
	FlushAsync(ResponseCallback) *ReqRes
	EchoAsync(string, ResponseCallback) *ReqRes
	InfoAsync(types.RequestInfo, ResponseCallback) *ReqRes
	SetOptionAsync(types.RequestSetOption, ResponseCallback) *ReqRes
	DeliverTxAsync(types.RequestDeliverTx, ResponseCallback) *ReqRes
	CheckTxAsync(types.RequestCheckTx, ResponseCallback) *ReqRes
	QueryAsync(types.RequestQuery, ResponseCallback) *ReqRes
	CommitAsync(ResponseCallback) *ReqRes
	InitChainAsync(types.RequestInitChain, ResponseCallback) *ReqRes
	BeginBlockAsync(types.RequestBeginBlock, ResponseCallback) *ReqRes
	EndBlockAsync(types.RequestEndBlock, ResponseCallback) *ReqRes
	BeginRecheckTxAsync(types.RequestBeginRecheckTx, ResponseCallback) *ReqRes
	EndRecheckTxAsync(types.RequestEndRecheckTx, ResponseCallback) *ReqRes
	ListSnapshotsAsync(types.RequestListSnapshots, ResponseCallback) *ReqRes
	OfferSnapshotAsync(types.RequestOfferSnapshot, ResponseCallback) *ReqRes
	LoadSnapshotChunkAsync(types.RequestLoadSnapshotChunk, ResponseCallback) *ReqRes
	ApplySnapshotChunkAsync(types.RequestApplySnapshotChunk, ResponseCallback) *ReqRes
	FlushSync() (*types.ResponseFlush, error)
	EchoSync(string) (*types.ResponseEcho, error)
	InfoSync(types.RequestInfo) (*types.ResponseInfo, error)
	SetOptionSync(types.RequestSetOption) (*types.ResponseSetOption, error)
	DeliverTxSync(types.RequestDeliverTx) (*types.ResponseDeliverTx, error)
	CheckTxSync(types.RequestCheckTx) (*types.ResponseCheckTx, error)
	QuerySync(types.RequestQuery) (*types.ResponseQuery, error)
	CommitSync() (*types.ResponseCommit, error)
	InitChainSync(types.RequestInitChain) (*types.ResponseInitChain, error)
	BeginBlockSync(types.RequestBeginBlock) (*types.ResponseBeginBlock, error)
	EndBlockSync(types.RequestEndBlock) (*types.ResponseEndBlock, error)
	BeginRecheckTxSync(types.RequestBeginRecheckTx) (*types.ResponseBeginRecheckTx, error)
	EndRecheckTxSync(types.RequestEndRecheckTx) (*types.ResponseEndRecheckTx, error)
	ListSnapshotsSync(types.RequestListSnapshots) (*types.ResponseListSnapshots, error)
	OfferSnapshotSync(types.RequestOfferSnapshot) (*types.ResponseOfferSnapshot, error)
	LoadSnapshotChunkSync(types.RequestLoadSnapshotChunk) (*types.ResponseLoadSnapshotChunk, error)
	ApplySnapshotChunkSync(types.RequestApplySnapshotChunk) (*types.ResponseApplySnapshotChunk, error)
}