NPE in Domain Classes Dependencies window

**IDE version, OS**:

### Steps to reproduce

1. Clone [grails-core](https://github.com/apache/grails-core)
2. Open `./grails-core/grails-test-examples/mongodb/springboot/src/main/groovy/example/Book.groovy`
3. Switch to `Domain classes dependencies tab`

### Actual result
```java
java.lang.IllegalStateException: @NotNull method com/intellij/openapi/graph/impl/view/JBGraph2DView.getCoarseGridColor must not return null
at com.intellij.openapi.graph.impl.view.JBGraph2DView.$$$reportNull$$$0(JBGraph2DView.java)
at com.intellij.openapi.graph.impl.view.JBGraph2DView.getCoarseGridColor(JBGraph2DView.java:27)
at com.intellij.openapi.graph.impl.view.JBBackgroundRenderer.paint(JBBackgroundRenderer.java:89)
at y.view.Graph2DCanvas.b(Unknown Source)
at y.view.Graph2DCanvas.g(Unknown Source)
at y.view.Graph2DCanvas.paintComponent(Unknown Source)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1124)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at com.intellij.openapi.fileEditor.impl.EditorTabs.paintChildren(EditorTabbedContainer.kt:612)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JLayeredPane.paint(JLayeredPane.java:586)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JLayeredPane.paint(JLayeredPane.java:586)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1133)
at java.desktop/javax.swing.JLayeredPane.paint(JLayeredPane.java:586)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:964)
at java.desktop/javax.swing.JComponent.paintToOffscreen(JComponent.java:5326)
at java.desktop/javax.swing.BufferStrategyPaintManager.paint(BufferStrategyPaintManager.java:256)
at java.desktop/javax.swing.RepaintManager.paint(RepaintManager.java:1352)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1110)
at java.desktop/java.awt.GraphicsCallback$PaintCallback.run(GraphicsCallback.java:39)
at java.desktop/sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:75)
at java.desktop/sun.awt.SunGraphicsCallback.runComponents(SunGraphicsCallback.java:112)
at java.desktop/java.awt.Container.paint(Container.java:2005)
at java.desktop/java.awt.Window.paint(Window.java:3989)
at com.intellij.openapi.wm.impl.IdeFrameImpl.paint(IdeFrameImpl.kt:141)
at java.desktop/javax.swing.RepaintManager$4.run(RepaintManager.java:898)
at java.desktop/javax.swing.RepaintManager$4.run(RepaintManager.java:870)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.desktop/javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:870)
at java.desktop/javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:843)
at java.desktop/javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:789)
at java.desktop/javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1921)
at com.intellij.util.concurrency.ChildContext$runInChildContext$1.invoke(propagation.kt:167)
at com.intellij.util.concurrency.ChildContext$runInChildContext$1.invoke(propagation.kt:167)
at com.intellij.util.concurrency.ChildContext.runInChildContext(propagation.kt:173)
at com.intellij.util.concurrency.ChildContext.runInChildContext(propagation.kt:167)
at com.intellij.util.concurrency.ContextRunnable.run(ContextRunnable.java:27)
at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:318)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:781)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:728)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:722)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:750)
at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.kt:589)
at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.kt:486)
at com.intellij.ide.IdeEventQueue.dispatchEvent$lambda$12$lambda$11$lambda$10$lambda$9(IdeEventQueue.kt:311)
at com.intellij.openapi.progress.impl.CoreProgressManager.computePrioritized(CoreProgressManager.java:885)
at com.intellij.ide.IdeEventQueue.dispatchEvent$lambda$12$lambda$11$lambda$10(IdeEventQueue.kt:310)
at com.intellij.ide.IdeEventQueueKt.performActivity$lambda$3(IdeEventQueue.kt:962)
at com.intellij.openapi.application.TransactionGuardImpl.performActivity(TransactionGuardImpl.java:110)
at com.intellij.ide.IdeEventQueueKt.performActivity(IdeEventQueue.kt:962)
at com.intellij.ide.IdeEventQueue.dispatchEvent$lambda$12(IdeEventQueue.kt:305)
at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.kt:337)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:207)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:92)
```
### Expected result
No exceptions

---

*Imported from [IDEA-373245](https://youtrack.jetbrains.com/issue/IDEA-373245) · Type: Bug · Votes: 0*
*Comments, attachments, dates and reporter are not part of the export — follow the link above for the full history.*

Reproduce the failure by opening grails-test-examples/mongodb/springboot/src/main/groovy/example/Book.groovy and switching to the Domain classes dependencies tab. Start with the stack-trace entry points JBGraph2DView.getCoarseGridColor and JBBackgroundRenderer.paint. Done means the tab opens without exceptions.

Written by the indexing model from the issue text.