rpcclient

type Client interface {
	HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error)
	HeaderByNumber(ctx context.Context, number *big.Int) (*miniheader.MiniHeader, error)
	FilterLogs(ctx context.Context, q FilterQuery) ([]types.Log, error)
	CallContext(ctx context.Context, result interface{}, method string, args ...interface{}) error
	CodeAt(ctx context.Context, contract common.Address, blockNumber *big.Int) ([]byte, error)
	CallContract(ctx context.Context, call klaytn.CallMsg, blockNumber *big.Int) ([]byte, error)
	GetRateLimitDroppedRequests() int64
}

type FilterQuery struct {
	BlockHash *common.Hash     // used by klay_getLogs, return logs only from block with this hash
	FromBlock *big.Int         // beginning of the queried range, nil means genesis block
	ToBlock   *big.Int         // end of the range, nil means latest block
	Addresses []common.Address // restricts matches to events created by specific contracts

	// The Topic list restricts matches to particular event topics. Each event has a list
	// of topics. Topics matches a prefix of that list. An empty element slice matches any
	// topic. Non-empty elements represent an alternative that matches any of the
	// contained topics.
	//
	// Examples:
	// {} or nil          matches any topic list
	// {{A}}              matches topic A in first position
	// {{}, {B}}          matches any topic in first position AND B in second position
	// {{A}, {B}}         matches topic A in first position AND B in second position
	// {{A, B}, {C, D}}   matches topic (A OR B) in first position AND (C OR D) in second position
	Topics [][]common.Hash
}