@classmethod
def walk(cls, obj, data):
    """
        Validate the given data against a schema.

        Args:
            obj (.Schema):
                Description of the data format.
            data:
                Input data to validate.

        Raises:
            Invalid:
                When a key or value doesn't match the accepted type for that field.

        Returns:
            Parsed data with optional values filled in.
        """
    return super().walk(obj, data)
