def create_yaml_workflow_schema() -> str:
    """Return dummy YAML workflow schema."""
    reana_yaml_schema = """
        version: 0.7.2
        inputs:
          files:
            - code/helloworld.py
            - inputs/names.txt
          parameters:
            sleeptime: 2
            inputfile: inputs/names.txt
            helloworld: code/helloworld.py
            outputfile: outputs/greetings.txt
        outputs:
          files:
           - outputs/greetings.txt
        workflow:
          type: serial
          specification:
            steps:
              - environment: 'python:2.7'
                commands:
                  - python "${helloworld}" --sleeptime ${sleeptime} \
                  --inputfile "${inputfile}" --outputfile "${outputfile}"
        """
    return reana_yaml_schema