some unstable APIs marked with ApiStatus.Experimental annotation

platform/editor-ui-api/src/com/intellij/openapi/editor/Inlay.java

@@ -17,6 +17,7 @@ package com.intellij.openapi.editor;
 
 import com.intellij.openapi.Disposable;
 import com.intellij.openapi.util.UserDataHolderEx;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
 /**
@@ -27,6 +28,7 @@ import org.jetbrains.annotations.NotNull;
  * <p>
  * WARNING! This is an experimental API, it can change at any time.
  */
+@ApiStatus.Experimental
 public interface Inlay extends Disposable, UserDataHolderEx {
   /**
    * Tells whether this element is valid. Inlay becomes invalid on explicit disposal,

platform/editor-ui-api/src/com/intellij/openapi/editor/InlayModel.java

@@ -16,6 +16,7 @@
 package com.intellij.openapi.editor;
 
 import com.intellij.openapi.Disposable;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -28,6 +29,7 @@ import java.util.List;
  * <p>
  * WARNING! This is an experimental API, it can change at any time.
  */
+@ApiStatus.Experimental
 public interface InlayModel {
   /**
    * Introduces an inline visual element at a given offset, its width and appearance is defined by the provided renderer. With respect to

platform/projectModel-impl/src/com/intellij/openapi/roots/AdditionalLibraryRootsProvider.java

@@ -18,6 +18,7 @@ package com.intellij.openapi.roots;
 import com.intellij.openapi.extensions.ExtensionPointName;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.vfs.VirtualFile;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Collection;
@@ -32,6 +33,7 @@ import java.util.Collections;
  *
  * Please note it is an experimental API that is subject to incompatible changes, or even removal, in a future release.
  */
+@ApiStatus.Experimental
 public abstract class AdditionalLibraryRootsProvider {
   public static final ExtensionPointName<AdditionalLibraryRootsProvider> EP_NAME = ExtensionPointName.create("com.intellij.additionalLibraryRootsProvider");
 

platform/xdebugger-impl/src/com/intellij/xdebugger/attach/XLocalAttachGroup.java

@@ -18,10 +18,12 @@ package com.intellij.xdebugger.attach;
 import com.intellij.execution.process.ProcessInfo;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.UserDataHolder;
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
 import javax.swing.*;
 
+@ApiStatus.Experimental
 public interface XLocalAttachGroup {
   int getOrder();