cfgsections() {
		L.error('InternalError', 'Not implemented');
	}
Enumerate the UCI section IDs covered by this form section element.

@abstract
@throws {InternalError}
Throws an `InternalError` exception if the function is not implemented.

@returns {string[]}
Returns an array of UCI section IDs covered by this form element.
The sections will be rendered in the same order as the returned array.