code: def create(backbone: ModelFactory, vmin: float, vmax: float, atoms: int,
             input_block: typing.Optional[ModelFactory]=None):
      
      if input_block is None:
          input_block = IdentityFactory()
  
      return QDistributionalModelFactory(
          input_block=input_block, backbone=backbone,
          vmin=vmin,
          vmax=vmax,
          atoms=atoms
      )
docs: Vel factory function