code: def _extract_from_subworkflow(vs, step):
      
      substep_ids = set([x.name for x in step.workflow])
      out = []
      for var in vs:
          internal = False
          parts = var["id"].split("/")
          if len(parts) > 1:
              if parts[0] in substep_ids:
                  internal = True
          if not internal:
              var.pop("source", None)
              out.append(var)
      return out
docs: Remove internal variable names when moving from sub-workflow to main.