registerHelper static method
Registers a helper value with the given name in the given namespace (type). This is used to define functionality that may be looked up by mode. Will create (if it doesn't already exist) a property on the CodeMirror object for the given type, pointing to an object that maps names to values. I.e. after doing CodeMirror.registerHelper("hint", "foo", myFoo), the value CodeMirror.hint.foo will point to myFoo.
Implementation
static void registerHelper(String type, String mode, dynamic helper) {
_cm!.callMethod('registerHelper', [type, mode, helper]);
}