kotlin-fork/annotations/com/intellij/openapi/vfs/annotations.xml

<root>
  <item
      name='com.intellij.openapi.vfs.VirtualFile com.intellij.openapi.vfs.VirtualFile createChildDirectory(java.lang.Object, java.lang.String)'>
    <annotation name='org.jetbrains.annotations.NotNull'/>
  </item>
</root>