cwlVersion: v1.0 class: Workflow dct:creator: '@id': http://orcid.org/0000-0002-7681-6415 foaf:name: Brian O'Connor foaf:mbox: mailto:briandoconnor@gmail.com dct:contributor: foaf:name: Denis Yuen foaf:mbox: mailto:denis.yuen@oicr.on.ca requirements: - class: SubworkflowFeatureRequirement inputs: input_file: File outputs: workflow_output_file: type: File outputSource: checker/results_file steps: md5sum: run: md5sum/md5sum.cwl in: input_file: input_file out: [output_file] checker: run: checker/md5sum_checker.cwl in: input_file: md5sum/output_file out: [results_file] doc: | This demonstrates how to wrap a "real" workflow with a checker workflow that runs both the tool and a tool that performs verification of results