code: def create_pull_from_issue(self, issue, base, head):
          
          if int(issue) > 0:
              data = {'issue': issue, 'base': base, 'head': head}
              return self._create_pull(data)
          return None
docs: Create a pull request from issue #``issue``.
  
          :param int issue: (required), issue number
          :param str base: (required), e.g., 'master'
          :param str head: (required), e.g., 'username:branch'
          :returns: :class:`PullRequest <github3.pulls.PullRequest>` if
              successful, else None