docs: def check(self, return_code=0):
          """Run command with arguments. Wait for command to complete. If the
          exit code was as expected and there is no exception then return,
          otherwise raise EasyProcessError.
  
          :param return_code: int, expected return code
          :rtype: self
  
          """
          ret = self.call().return_code
          ok = ret == return_code
          if not ok:
              raise EasyProcessError(
                  self, 'check error, return code is not {0}!'.format(return_code))
          return self