How to use the cwlts/models.isType function in cwlts

this.workflowWrapper.steps[0].in.forEach((input: WorkflowStepInputModel) => {

                if (isType(input, ["File", "Directory"])) {
                    // create inputs from file ports
                    this.workflowWrapper.createInputFromPort(input);
                } else {
                    // everything else should be exposed (show up in the step inspector)
                    this.workflowWrapper.exposePort(input);
                }
            });