Add instantiate method on ParameterizedType and InterfaceType.

pkg/analysis_server/lib/src/services/refactoring/extract_method.dart

Index: pkg/analysis_server/lib/src/services/refactoring/extract_method.dart
diff --git a/pkg/analysis_server/lib/src/services/refactoring/extract_method.dart b/pkg/analysis_server/lib/src/services/refactoring/extract_method.dart
index 1cb713a1b293973ffe99b32346d24783c54a7e62..b2223d0d542afc2b0fd3eed5bf40397b25dccbfb 100644
--- a/pkg/analysis_server/lib/src/services/refactoring/extract_method.dart
+++ b/pkg/analysis_server/lib/src/services/refactoring/extract_method.dart
@@ -667,7 +667,7 @@ class ExtractMethodRefactoringImpl extends RefactoringImpl
       variableType = _getTypeCode(_returnType);
       if (_hasAwait) {
         if (_returnType.element != futureType.element) {
-          returnType = _getTypeCode(futureType.substitute4([_returnType]));
+          returnType = _getTypeCode(futureType.instantiate([_returnType]));
         }
       } else {
         returnType = variableType;