src/vs/workbench/common/editor.ts/EditorInputFactoryRegistry/registerFileEditorInputFactory
class EditorInputFactoryRegistry:	registerFileEditorInputFactory(factory: IFileEditorInputFactory): void {
		if (this.fileEditorInputFactory) {
			throw new Error('Can only register one file editor input factory.');
		}

		this.fileEditorInputFactory = factory;
	}