def __get_grants(self, target_file, all_grant_data):
        """
        Return grant permission, grant owner, grant owner email and grant id  as a list.
        It needs you to set k.key to a key on amazon (file path) before running this.
        note that Amazon returns a list of grants for each file.

        options:
            - private: Owner gets FULL_CONTROL. No one else has any access rights.
            - public-read: Owners gets FULL_CONTROL and the anonymous principal is granted READ access.
            - public-read-write: Owner gets FULL_CONTROL and the anonymous principal is granted READ and WRITE access.
            - authenticated-read: Owner gets FULL_CONTROL and any principal authenticated as a registered Amazon S3 user is granted READ access

        """
        self.k.key = target_file

        the_grants = self.k.get_acl().acl.grants

        grant_list = []

        for grant in the_grants:
            if all_grant_data:
                grant_list.append(
                    {"permission": grant.permission, "name": grant.display_name, "email": grant.email_address, "id": grant.id})
            else:
                grant_list.append({"permission": grant.permission, "name": grant.display_name})

        return grant_list