def locked_get(self):
        credentials = None
        self._validate_file()
        try:
            f = open(self._filename, 'rb')
            content = f.read()
            f.close()
        except IOError:
            return credentials

        try:
            credentials = Credentials.new_from_json(content)
            credentials.set_store(self)
        except ValueError:
            pass

        return credentials
Retrieve Credential from file.
dataset/ETHPy150Open google/oauth2client/oauth2client/file.py/Storage.locked_get