code: def build(self, client, pull=False, usecache=True):
          
          stage = staging.StagedFile(self.sourceimage, self.sourcepath, self.destpath,
                                     cache_from=self.cache_from)
          stage.stage(self.baseimage, self.buildname)
docs: Note:
              `pull` and `usecache` are for compatibility only. They're irrelevant because
              hey were applied when BUILDING self.sourceimage