Enhance the change builders

pkg/analysis_server/lib/src/provisional/edit/utilities/change_builder_core.dart

Index: pkg/analysis_server/lib/src/provisional/edit/utilities/change_builder_core.dart
diff --git a/pkg/analysis_server/lib/src/provisional/edit/utilities/change_builder_core.dart b/pkg/analysis_server/lib/src/provisional/edit/utilities/change_builder_core.dart
index 8fbcbdf48989e1921b96f3ba6565d65c06e69e68..28f42c81addee1f435ce16cdff63bf051cf3ba25 100644
--- a/pkg/analysis_server/lib/src/provisional/edit/utilities/change_builder_core.dart
+++ b/pkg/analysis_server/lib/src/provisional/edit/utilities/change_builder_core.dart
@@ -93,6 +93,28 @@ abstract class FileEditBuilder {
    */
   void addReplacement(
       int offset, int length, void buildEdit(EditBuilder builder));
+
+  /**
+   * Add an insertion of the given [text] at the given [offset]. The [offset] is
+   * relative to the original source. This is fully equivalent to
+   *
+   *     addInsertion(offset, (EditBuilder builder) {
+   *       builder.write(text);
+   *     });
+   */
+  void addSimpleInsertion(int offset, String text);
+
+  /**
+   * Add a replacement of the text starting at the given [offset] and continuing
+   * for the given [length]. The [offset] is relative to the original source.
+   * The original content will be replaced by the given [text]. This is fully
+   * equivalent to
+   *
+   *     addReplacement(offset, length, (EditBuilder builder) {
+   *       builder.write(text);
+   *     });
+   */
+  void addSimpleReplacement(int offset, int length, String text);
 }
 
 /**