Creates an instance of this client using the provided credentials
        file.

        Args:
            filename (str): The path to the service account private key json
                file.
            args: Additional arguments to pass to the constructor.
            kwargs: Additional arguments to pass to the constructor.

        Returns:
            dialogflow_v2.SessionEntityTypesClient: The constructed client.

def from_service_account_file(cls, filename, *args, **kwargs):
        """Creates an instance of this client using the provided credentials
        file.

        Args:
            filename (str): The path to the service account private key json
                file.
            args: Additional arguments to pass to the constructor.
            kwargs: Additional arguments to pass to the constructor.

        Returns:
            dialogflow_v2.SessionEntityTypesClient: The constructed client.
        """
        credentials = service_account.Credentials.from_service_account_file(
            filename)
        kwargs['credentials'] = credentials
        return cls(*args, **kwargs)