code: def _check_requirements(self):
          
  
          path = self._vpcs_path()
          if not path:
              raise VPCSError("No path to a VPCS executable has been set")
  
          # This raise an error if ubridge is not available
          self.ubridge_path
  
          if not os.path.isfile(path):
              raise VPCSError("VPCS program '{}' is not accessible".format(path))
  
          if not os.access(path, os.X_OK):
              raise VPCSError("VPCS program '{}' is not executable".format(path))
  
          yield from self._check_vpcs_version()
docs: Check if VPCS is available with the correct version.