/*
 * Copyright 2000-2014 JetBrains s.r.o.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.intellij.ide.projectView;

import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.util.containers.HashSet;
import org.jetbrains.annotations.NotNull;

import java.util.Collection;
import java.util.Set;

public interface RootsProvider {

  Set<VirtualFile> EMPTY_ROOTS = new HashSet<VirtualFile>();

  @NotNull
  Collection<VirtualFile> getRoots();

}

@@ -682,53 +682,8 @@
 le;%0A
-import com.intellij.util.containers.HashSet;%0A
 impo
@@ -750,16 +750,46 @@
 ection;%0A
+import java.util.Collections;%0A
 import j
@@ -874,32 +874,28 @@
 S = 
-new HashSet%3CVirtualFile%3E
+Collections.emptySet
 ();%0A

make RootsProvider.EMPTY_ROOTS unmodifiable