get_parameter_values! is confusingly named

[glwagner]

because it does not return values, it returns "pairs":

function ThermodynamicsParameters(toml_dict)

    # Used in thermodynamics, from parameter file
    aliases = [ ..., "gas_constant", "molmass_dryair"]

    param_pairs = CLIMAParameters.get_parameter_values!(
        toml_dict,
        aliases,
        "Thermodynamics",
    )
    nt = (; param_pairs...)

    FT = CP.float_type(toml_dict)
    return ThermodynamicsParameters{FT}(; nt...)
end

from the docs.

cc @odunbar