Workaround the stupid issue of object.opEquals having to be @system inpure throw. The @gc would be fine still.
If the radio button is pressed, then it sets to unpressed. Does nothing otherwise.
Sets the radio button into its pressed state.
Sets the group of the radio button.
Returns the assigned value of the radio button.
Radio button interface. Can be used to implement radio button style behavior on almost any component that implements this interface.