extensions/php-language-features/src/features/validationProvider.ts/PHPValidationProvider/dispose
class PHPValidationProvider:	public dispose(): void {
		if (this.diagnosticCollection) {
			this.diagnosticCollection.clear();
			this.diagnosticCollection.dispose();
		}
		if (this.documentListener) {
			this.documentListener.dispose();
			this.documentListener = null;
		}
	}