docs: def _error_on_missing_application(self, params):
          """ Raise an ApplicationNotFoundError if the app is not accessible
  
              This method checks in the system path (usually $PATH) or for
              the existence of self._command. If self._command is not found
              in either place, an ApplicationNotFoundError is raised to
              inform the user that the application they are trying to access is
              not available.
  
              This method should be overwritten when self._command does not
              represent the relevant executable (e.g., self._command = 'prog -a')
              or in more complex cases where the file to be executed may be
              passed as a parameter (e.g., with java jar files, where the
              jar file is passed to java via '-jar'). It can also be overwritten
              to by-pass testing for application presence by never raising an
              error.
          """
          command = self._command
          # strip off " characters, in case we got a FilePath object
          found_in_path = which(command.strip('"')) is not None
          if not (exists(command) or found_in_path):
              raise ApplicationNotFoundError("Cannot find %s. Is it installed? "
                                             "Is it in your path?" % command)