Sort the containing method first in completions following super

pkg/analysis_server/test/services/completion/prefixed_element_contributor_test.dart

Index: pkg/analysis_server/test/services/completion/prefixed_element_contributor_test.dart
diff --git a/pkg/analysis_server/test/services/completion/prefixed_element_contributor_test.dart b/pkg/analysis_server/test/services/completion/prefixed_element_contributor_test.dart
index 65cb9a432df9294673b6f8f2c8d0d2b56b532f18..8015d8ffc3379cc2bda0e8162c28e42a38b47e57 100644
--- a/pkg/analysis_server/test/services/completion/prefixed_element_contributor_test.dart
+++ b/pkg/analysis_server/test/services/completion/prefixed_element_contributor_test.dart
@@ -557,7 +557,8 @@ class C1 extends C2 implements C3 {
       assertNotSuggested('fs2');
       assertSuggestInvocationMethod('mi2', 'C2', null);
       assertNotSuggested('ms2');
-      assertSuggestInvocationMethod('m', 'C2', null);
+      assertSuggestInvocationMethod('m', 'C2', null,
+          relevance: DART_RELEVANCE_HIGH);
       assertNotSuggested('fi3');
       assertNotSuggested('fs3');
       assertNotSuggested('mi3');