The license of the program, as a value of the gtk.types.License enumeration.
The #GtkAboutDialog will automatically fill out a standard disclaimer and link the user to the appropriate online resource for the license text.
If gtk.types.License.Unknown is used, the link used will be the same specified in the #GtkAboutDialog:website property.
If gtk.types.License.Custom is used, the current contents of the #GtkAboutDialog:license property are used.
For any other #GtkLicense value, the contents of the #GtkAboutDialog:license property are also set by this property as a side effect.
Builder instance for fluent chaining
Set licenseType property.