'Add or delete projects.
:param:to_add: A list of projects to add
:param:to_delete: A list of projects to remove'

@base.remotable
def save_projects(self, to_add=None, to_delete=None):

    to_add = (to_add if (to_add is not None) else [])
    to_delete = (to_delete if (to_delete is not None) else [])
    for project_id in to_add:
        self._add_access(project_id)
    for project_id in to_delete:
        self._remove_access(project_id)
    self.obj_reset_changes(['projects'])
