Swift.KeyedDecodingContainer.func decode<T, C>(_: CodableConfiguration<T?, C>.Type, forKey key: KeyedDecodingContainer<K>.Key) throws -> CodableConfiguration<T?, C> where T : DecodableWithConfiguration, T : EncodableWithConfiguration, C : DecodingConfigurationProviding, C : EncodingConfigurationProviding, T.DecodingConfiguration == C.DecodingConfiguration, T.EncodingConfiguration == C.EncodingConfiguration