code: def check(self):
          
          if self.sparselib not in self.sparselib_alt:
              logger.warning("Invalid sparse library <{}>".format(self.sparselib))
              self.sparselib = 'umfpack'
  
          if self.sparselib == 'klu' and not KLU:
              logger.info("Optional package \"cvxoptklu\" available for speed up")
              self.sparselib = 'umfpack'
  
          return True
docs: Check config data consistency
  
          Returns
          -------