Load an account from a keystore file.

        Args:
            path: full path to the keyfile
            password: the password to decrypt the key file or `None` to leave it encrypted

def load(cls, path: str, password: str = None) -> 'Account':
        """Load an account from a keystore file.

        Args:
            path: full path to the keyfile
            password: the password to decrypt the key file or `None` to leave it encrypted
        """
        with open(path) as f:
            keystore = json.load(f)
        if not check_keystore_json(keystore):
            raise ValueError('Invalid keystore file')
        return Account(keystore, password, path=path)