Vel factory function

def create(backbone: ModelFactory, vmin: float, vmax: float, atoms: int, initial_std_dev: float = 0.4,
           factorized_noise: bool = True, input_block: typing.Optional[ModelFactory] = None):
    """ Vel factory function """
    if input_block is None:
        input_block = IdentityFactory()

    return QDistributionalModelFactory(
        input_block=input_block, backbone=backbone,
        vmin=vmin,
        vmax=vmax,
        atoms=atoms,
        initial_std_dev=initial_std_dev,
        factorized_noise=factorized_noise
    )