src/vs/workbench/common/editor/textResourceEditorInput.ts/AbstractTextResourceEditorInput/getViewStateFor
class AbstractTextResourceEditorInput:	protected getViewStateFor(group: GroupIdentifier): IEditorViewState | undefined {
		for (const editorPane of this.editorService.visibleEditorPanes) {
			if (editorPane.group.id === group && this.matches(editorPane.input)) {
				if (isTextEditorPane(editorPane)) {
					return editorPane.getViewState();
				}
			}
		}

		return undefined;
	}