method chain completion: suggest chains for collection of elements

java/java-tests/testData/codeInsight/completion/methodChains/testCollection/TestCompletion.java

@@ -0,0 +1,18 @@
+import java.jang.String;
+import java.util.*;
+
+class PsiMethod {
+}
+
+interface PsiClass {
+  List<PsiMethod> getMethods();
+}
+
+public class TestCompletion {
+
+  PsiClass c;
+
+  public void method() {
+    Collection<PsiMethod> m = <caret>
+  }
+}

java/java-tests/testData/codeInsight/completion/methodChains/testCollection/TestIndex.java

@@ -0,0 +1,23 @@
+import java.util.*;
+
+
+public class TestIndex {
+
+  public void statMethod(PsiClass c) {
+    c.getMethods();
+    c.getMethods();
+    c.getMethods();
+    c.getMethods();
+    c.getMethods();
+    c.getMethods();
+    c.getMethods();
+    c.getMethods();
+  }
+}
+
+class PsiMethod {
+}
+
+interface PsiClass {
+  Collection<PsiMethod> getMethods();
+}

java/java-tests/testSrc/com/intellij/codeInsight/completion/MethodChainsCompletionTest.java

@@ -215,6 +215,11 @@ public class MethodChainsCompletionTest extends AbstractCompilerAwareTest {
     assertEquals("c.getMethods", element.getLookupString());
   }
 
+  public void testCollection() {
+    WeightableChainLookupElement element = assertOneElement(doCompletion());
+    assertEquals("c.getMethods", element.getLookupString());
+  }
+
   public void assertAdvisorLookupElementEquals(String lookupText,
                                                int unreachableParametersCount,
                                                int lastMethodWeight,