void () { configureByText("abc"); FoldRegion region = EditorTestUtil.addFoldRegion(myFixture.getEditor(), 0, 3, "...", false); region.setGutterMarkEnabledForSingleLine(true); verifyAnchors(null, 0, Type.EXPANDED_SINGLE_LINE); myFixture.getEditor().getFoldingModel().runBatchFoldingOperation(() -> region.setExpanded(false)); verifyAnchors(null, 0, Type.COLLAPSED_SINGLE_LINE); }