add @NotNull

diff --git a/platform/indexing-api/src/com/intellij/util/indexing/IndexableSetContributor.java b/platform/indexing-api/src/com/intellij/util/indexing/IndexableSetContributor.java
index bac287d4f6d5325d29d5c354a3e18591d33fe14a..06e841aba7059d5c6ba52091e923a14107edf219 100644 (file)
--- a/platform/indexing-api/src/com/intellij/util/indexing/IndexableSetContributor.java
+++ b/platform/indexing-api/src/com/intellij/util/indexing/IndexableSetContributor.java
@@ -21,7 +21,6 @@ import com.intellij.openapi.vfs.VirtualFileManager;
 import com.intellij.util.NotNullFunction;
 import com.intellij.util.containers.ContainerUtil;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
 
 import java.util.Collections;
 import java.util.HashSet;
@@ -67,9 +66,10 @@ public abstract class IndexableSetContributor implements IndexedRootsProvider {
   }
 
   @NotNull
-  public Set<VirtualFile> getAdditionalProjectRootsToIndex(@Nullable Project project) {
+  public Set<VirtualFile> getAdditionalProjectRootsToIndex(@NotNull Project project) {
     return EMPTY_FILE_SET;
   }
 
+  @NotNull
   public abstract Set<VirtualFile> getAdditionalRootsToIndex();
 }