def make_unique_field_name(self, root=""):
        """Makes a unique field name with the given root name for the
        collection.

        Args:
            root (""): an optional root for the output field name

        Returns:
            the field name
        """
        if not root:
            root = _get_random_characters(6)

        fields = self.get_field_schema()

        field_name = root
        if field_name in fields:
            field_name += "_" + _get_random_characters(6)

        while field_name in fields:
            field_name += _get_random_characters(1)

        return field_name
Makes a unique field name with the given root name for the
        collection.

        Args:
            root (""): an optional root for the output field name

        Returns:
            the field name
        
fiftyone/core/collections.py