Sets the parameter value for key if key is one of the parameter keys passed on instantiation or added by a subclass.
parameter key (case insensitive)
parameter value (will be sliced)
true if key is one of parameter keys passed on instantiation or added by a subclass or false otherwise. In case of false nothing has changed.
See Implementation
Sets the parameter value for key if key is one of the parameter keys passed on instantiation or added by a subclass.