def get_skeleton(self, field):
        """Gets the keypoint skeleton for the given field, or None if no
        skeleton is available.

        Skeletons are first retrieved from :meth:`skeletons` if they exist,
        otherwise from :meth:`default_skeleton`.

        Args:
            field: a field name

        Returns:
            a list of classes, or None
        """
        if field in self.skeletons:
            return self.skeletons[field]

        if self.default_skeleton:
            return self.default_skeleton

        return None
Gets the keypoint skeleton for the given field, or None if no
        skeleton is available.

        Skeletons are first retrieved from :meth:`skeletons` if they exist,
        otherwise from :meth:`default_skeleton`.

        Args:
            field: a field name

        Returns:
            a list of classes, or None
        
fiftyone/core/collections.py