original_docstring: 
      Take as input a field that should be used as key for that entity.
      See specification: https://www.apollographql.com/docs/federation/federation-spec/#key
  
      If the input contains a space it means it's a [compound primary key](https://www.apollographql.com/docs/federation/entities/#defining-a-compound-primary-key)
      which is not yet supported.
      
docstring: Take as input a field that should be used as key for that entity.
  
  If the input contains a space it means it's a [compound primary key]
  which is not yet supported.
docstring_tokens: Take as input a field that should be used as key for that entity . If the input contains a space it means it ' s a [ compound primary key ] which is not yet supported .
code: def key(fields: str):
      """
      Take as input a field that should be used as key for that entity.
      See specification: https://www.apollographql.com/docs/federation/federation-spec/#key
  
      If the input contains a space it means it's a [compound primary key](https://www.apollographql.com/docs/federation/entities/#defining-a-compound-primary-key)
      which is not yet supported.
      """
      if " " in fields:
          raise NotImplementedError("Compound primary keys are not supported.")
  
      def decorator(Type):
          # Check the provided fields actually exist on the Type.
          assert (
              fields in Type._meta.fields
          ), f'Field "{fields}" does not exist on type "{Type._meta.name}"'
  
          keys = getattr(Type, "_keys", [])
          keys.append(fields)
          setattr(Type, "_keys", keys)
  
          return Type
  
      return decorator
code_tokens: def key ( fields : str ) : if " " in fields : raise NotImplementedError ( "Compound primary keys are not supported." ) def decorator ( Type ) : assert ( fields in Type . _meta . fields ) , f'Field "{fields}" does not exist on type "{Type._meta.name}"' keys = getattr ( Type , "_keys" , [ ] ) keys . append ( fields ) setattr ( Type , "_keys" , keys ) return Type return decorator
short_docstring: Take as input a field that should be used as key for that entity.
short_docstring_tokens: Take as input a field that should be used as key for that entity .
comment: """
      Take as input a field that should be used as key for that entity.
      See specification: https://www.apollographql.com/docs/federation/federation-spec/#key
  
      If the input contains a space it means it's a [compound primary key](https://www.apollographql.com/docs/federation/entities/#defining-a-compound-primary-key)
      which is not yet supported.
      """$SEP$# Check the provided fields actually exist on the Type.