If a per-breed or per-good parameter is instantiated and then a breed or good is added, this function updates the parameter with the new breed or good and assigns it the default value specified at the
Param object’s instantiation.
WARNING: This is an internal function. Its use in user code is not recommended or supported, and its signature can change in future updates without warning. Use one of the suggested functions above instead, if applicable.
key — str, required
The name of the breed or good to be added.