Add more tests and explain some strange quotes.

api/resmap/resmap.go

@@ -246,5 +246,6 @@ type ResMap interface {
 	ApplySmPatch(
 		selectedSet *resource.IdSet, patch *resource.Resource) error
 
-	RemoveIdAnnotations() error
+	// Remove annotations used exclusively by the kustomize build process.
+	RemoveIdAnnotations()
 }

api/resmap/reswrangler.go

@@ -621,12 +621,8 @@ func (m *resWrangler) ApplySmPatch(
 	return nil
 }
 
-func (m *resWrangler) RemoveIdAnnotations() error {
+func (m *resWrangler) RemoveIdAnnotations() {
 	for _, r := range m.Resources() {
-		err := r.RemoveIdAnnotations()
-		if err != nil {
-			return err
-		}
+		r.RemoveIdAnnotations()
 	}
-	return nil
 }

api/resmap/reswrangler_test.go

@@ -998,7 +998,7 @@ spec:
 				return
 			}
 			assert.False(t, tc.errorExpected)
-			assert.NoError(t, m.RemoveIdAnnotations())
+			m.RemoveIdAnnotations()
 			yml, err := m.AsYaml()
 			assert.NoError(t, err)
 			assert.Equal(t, strings.Join(tc.expected, "---\n"), string(yml))
@@ -1111,7 +1111,7 @@ $patch: delete
 			assert.NoError(t, err, name)
 			assert.NoError(t, m.ApplySmPatch(idSet, p), name)
 			assert.Equal(t, tc.finalMapSize, m.Size(), name)
-			assert.NoError(t, m.RemoveIdAnnotations())
+			m.RemoveIdAnnotations()
 			yml, err := m.AsYaml()
 			assert.NoError(t, err, name)
 			assert.Equal(t, tc.expected, string(yml), name)