def __init__(self, dataStoreContractAddress, contractAbiFile):
        with open(contractAbiFile, 'r') as abi_definition:
            self.abi = json.load(abi_definition)
        self.dataStoreContractAddress = dataStoreContractAddress
        self.w3 = Web3(IPCProvider('/home/a/.ethereum/geth.ipc'))
        self.w3_contract = self.w3.eth.contract(self.abi, self.dataStoreContractAddress)