code: def create(self, repo_slug=None, key=None, label=None):
          
          key = '%s' % key
          repo_slug = repo_slug or self.bitbucket.repo_slug or ''
          url = self.bitbucket.url('SET_DEPLOY_KEY',
                                   username=self.bitbucket.username,
                                   repo_slug=repo_slug)
          return self.bitbucket.dispatch('POST',
                                         url,
                                         auth=self.bitbucket.auth,
                                         key=key,
                                         label=label)
docs: Associate an ssh key with your repo and return it.