model_type parameters are serialized but can be important defaults #41

In the output branch

classes like

class Cf(BedFriction):
    """Dimensionless friction coefficient formulation.

    Uses a constant dimensionless friction coefficient (c_f) to calculate
    bed shear stress. XBeach default bedfriccoef: 0.003 (range: 0.001-0.1).

    """

    model_type: Literal["cf"] = Field(
        default="cf",
        description="Model type discriminator",
    )

define a model_type that should be serialized as bedfriction = cf

I think this might be because exclude_unset is True in model_dump which causes this information to be dropped prior to it being available for flatten_nested_dict to dump correctly. AI suggested a number of fixes including patching flatten_nested_dict to reconstruct the model_type field or to turn off exclude_unset and use exclude_node in model_dump. I'm not confident enough with the implementation to put a pull request in at the moment. Seeking advice @rafa-guedes