A class stored as a resource. A class stored as a resource. The script exends the functionality of all objects that instance it. The 'new' method of a script subclass creates a new instance. [method Object.set_script] extends an existing object, if that object's class matches one of the script's base classes. Returns true if the script can be instanced. Returns true if the script, or a base class, defines a signal with the given name. Returns true if the script contains non-empty source code. Returns true if 'base_object' is an instance of this script. Returns true if the script is a tool script. A tool script can run in the editor. Reloads the script's class implementation. Returns an error code. The script source code, or an empty string if source code is not available. When set, does not reload the class implementation automatically.