def METHOD_NAME(self, instance, options):
    """Inspect data of instance to determine overridden options"""
    for key in instance.data:
        if key not in self.options:
            continue
        # Ensure the data is of correct type
        value = instance.data[key]
        if not isinstance(value, self.options[key]):
            self.log.warning(
                "Overridden attribute {key} was of "
                "the wrong type: {invalid_type} "
                "- should have been {valid_type}".format(
                    key=key,
                    invalid_type=type(value).__name__,
                    valid_type=self.options[key].__name__))
            continue
        options[key] = value
    return options