extract LibraryPrefixContributor from imported reference contributor

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

Index: pkg/analysis_server/test/services/completion/completion_test_util.dart
diff --git a/pkg/analysis_server/test/services/completion/completion_test_util.dart b/pkg/analysis_server/test/services/completion/completion_test_util.dart
index 6ac33a3ff359efa8467e03f2ab40637c4b336d14..7812fd8e8c4d92f55be1e14aae31e44e29ad61cf 100644
--- a/pkg/analysis_server/test/services/completion/completion_test_util.dart
+++ b/pkg/analysis_server/test/services/completion/completion_test_util.dart
@@ -1290,7 +1290,8 @@ abstract class AbstractSelectorSuggestionTest extends AbstractCompletionTest {
       assertSuggestImportedClass('EE');
       // hidden element suggested as low relevance
       //assertSuggestImportedClass('F', COMPLETION_RELEVANCE_LOW);
-      assertSuggestLibraryPrefix('g');
+      // Suggested by LibraryPrefixContributor
+      assertNotSuggested('g');
       assertNotSuggested('G');
       //assertSuggestImportedClass('H', COMPLETION_RELEVANCE_LOW);
       assertSuggestImportedClass('Object');
@@ -1401,7 +1402,8 @@ abstract class AbstractSelectorSuggestionTest extends AbstractCompletionTest {
       assertSuggestImportedClass('EE');
       // hidden element suggested as low relevance
       //assertSuggestImportedClass('F', COMPLETION_RELEVANCE_LOW);
-      assertSuggestLibraryPrefix('g');
+      // Suggested by LibraryPrefixContributor
+      assertNotSuggested('g');
       assertNotSuggested('G');
       //assertSuggestImportedClass('H', COMPLETION_RELEVANCE_LOW);
       assertSuggestImportedClass('Object');
@@ -1524,7 +1526,8 @@ abstract class AbstractSelectorSuggestionTest extends AbstractCompletionTest {
       assertSuggestImportedClass('EE');
       // hidden element suggested as low relevance
       //assertSuggestImportedClass('F', COMPLETION_RELEVANCE_LOW);
-      assertSuggestLibraryPrefix('g');
+      // Suggested by LibraryPrefixContributor
+      assertNotSuggested('g');
       assertNotSuggested('G');
       //assertSuggestImportedClass('H', COMPLETION_RELEVANCE_LOW);
       assertSuggestImportedClass('Object');
@@ -1631,7 +1634,8 @@ abstract class AbstractSelectorSuggestionTest extends AbstractCompletionTest {
       assertSuggestImportedClass('EE');
       // hidden element suggested as low relevance
       //assertSuggestImportedClass('F', COMPLETION_RELEVANCE_LOW);
-      assertSuggestLibraryPrefix('g');
+      // Suggested by LibraryPrefixContributor
+      assertNotSuggested('g');
       assertNotSuggested('G');
       //assertSuggestImportedClass('H', COMPLETION_RELEVANCE_LOW);
       assertSuggestImportedClass('Object');
@@ -2078,7 +2082,8 @@ abstract class AbstractSelectorSuggestionTest extends AbstractCompletionTest {
         expect(suggestionO.element.isPrivate, isFalse);
       }
       assertNotSuggested('T');
-      assertSuggestLibraryPrefix('x');
+      // Suggested by LibraryPrefixContributor
+      assertNotSuggested('x');
     });
   }
 
@@ -2101,7 +2106,8 @@ abstract class AbstractSelectorSuggestionTest extends AbstractCompletionTest {
       assertSuggestLocalClass('_B');
       assertSuggestImportedClass('Object');
       assertNotSuggested('T');
-      assertSuggestLibraryPrefix('x');
+      // Suggested by LibraryPrefixContributor
+      assertNotSuggested('x');
     });
   }
 
@@ -2124,7 +2130,8 @@ abstract class AbstractSelectorSuggestionTest extends AbstractCompletionTest {
       assertSuggestLocalClass('_B');
       assertSuggestImportedClass('String');
       assertNotSuggested('T');
-      assertSuggestLibraryPrefix('x');
+      // Suggested by LibraryPrefixContributor
+      assertNotSuggested('x');
     });
   }
 
@@ -2147,7 +2154,8 @@ abstract class AbstractSelectorSuggestionTest extends AbstractCompletionTest {
       assertSuggestLocalClass('_B');
       assertSuggestImportedClass('String');
       assertNotSuggested('Sew');
-      assertSuggestLibraryPrefix('Soo');
+      // Suggested by LibraryPrefixContributor
+      assertNotSuggested('Soo');
     });
   }
 
@@ -2170,7 +2178,8 @@ abstract class AbstractSelectorSuggestionTest extends AbstractCompletionTest {
       assertSuggestLocalClass('_B');
       assertSuggestImportedClass('Object');
       assertNotSuggested('T');
-      assertSuggestLibraryPrefix('x');
+      // Suggested by LibraryPrefixContributor
+      assertNotSuggested('x');
     });
   }
 
@@ -2193,7 +2202,8 @@ abstract class AbstractSelectorSuggestionTest extends AbstractCompletionTest {
       assertSuggestLocalClass('_B');
       assertSuggestImportedClass('Object');
       assertNotSuggested('T');
-      assertSuggestLibraryPrefix('x');
+      // Suggested by LibraryPrefixContributor
+      assertNotSuggested('x');
     });
   }