Imports
- github.com/codestates/WBA-BC-Project-02/common/enum
- github.com/codestates/WBA-BC-Project-02/was/common
- github.com/codestates/WBA-BC-Project-02/was/logger
- github.com/ethereum/go-ethereum/common
- github.com/ethereum/go-ethereum/core/types
- github.com/ethereum/go-ethereum/ethclient