docs: def get(self, entry):
          """
          get the value from vault secret backend
          """
          if self.apiVersion == 1:
              path = self.secretsmount + '/' + entry
          else:
              path = self.secretsmount + '/data/' + entry
  
          # note that the HTTP path contains v1 for both versions of the key-value
          # secret engine. Different versions of the key-value engine are
          # effectively separate secret engines in vault, with the same base HTTP
          # API, but with different paths within it.
          proj = yield self._http.get('/v1/{0}'.format(path))
          code = yield proj.code
          if code != 200:
              raise KeyError("The key %s does not exist in Vault provider: request"
                             " return code:%d." % (entry, code))
          json = yield proj.json()
          if self.apiVersion == 1:
              ret = json.get('data', {}).get('value')
          else:
              ret = json.get('data', {}).get('data', {}).get('value')
          return ret