def METHOD_NAME(self, stash_rev: str, rev: str):
    """Selectively apply changes from stash_rev.
    Only changes to files from left which do not exist in right will be applied.
    """
    self._copy_difference(stash_rev, rev)
    commit = self.scm.resolve_commit(stash_rev)
    for parent_rev in commit.parents:
        parent_commit = self.scm.resolve_commit(parent_rev)
        if parent_commit.message.startswith("untracked files on "):
            self._copy_difference(parent_rev, rev)