Tweak comment wording

pkgs/checks_codegen/lib/src/builder.dart

diff --git a/pkgs/checks_codegen/lib/src/builder.dart b/pkgs/checks_codegen/lib/src/builder.dart
index fdc5e32..070cefc 100644
--- a/pkgs/checks_codegen/lib/src/builder.dart
+++ b/pkgs/checks_codegen/lib/src/builder.dart
@@ -130,8 +130,8 @@
 
   /// Whether [field] should get a `has` getter.
   ///
-  /// Private fields are skipped because the generated extension is in a
-  /// different library and cannot access them.
+  /// Checks whether the field can be referenced on an instance of the class
+  /// containing [field] from the generated library.
   bool _isCheckableField(FieldElement field) =>
       field.name != 'hashCode' &&
       !field.isStatic &&