docs: def from_dict(cls, dictionary):
          """Create a MetadataRb instance from a dict."""
          cookbooks = set()
          # put these in order
          groups = [cookbooks]
  
          for key, val in dictionary.items():
              if key == 'depends':
                  cookbooks.update({cls.depends_statement(cbn, meta)
                                    for cbn, meta in val.items()})
  
          body = ''
          for group in groups:
              if group:
                  body += '\n'
              body += '\n'.join(group)
          return cls.from_string(body)