docs: def iteryaml(self, *args, **kwargs):
          """Yields the data structures from iterstruct as YAML strings"""
          from rowgenerators.rowpipe.json import VTEncoder
          import yaml
  
          if 'cls' not in kwargs:
              kwargs['cls'] = VTEncoder
  
          for s in self.iterstruct:
              yield (yaml.safe_dump(s))