<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def all(self):
 """Get all collaborators. Returns: List[str]: Collaborators. """

        return [email for email, action in self._collaborators.items() if action in [RoleValue.Owner, RoleValue.User, ShareRequestValue.Add]]