diff --git a/android/util.go b/android/util.go
index 0ee253e..47c4583 100644
--- a/android/util.go
+++ b/android/util.go
@@ -65,21 +65,55 @@
 	return buf.String()
 }
 
-// SorterStringKeys returns the keys of the given string-keyed map in the ascending order
+// SorterStringKeys returns the keys of the given string-keyed map in the ascending order.
 func SortedStringKeys(m interface{}) []string {
 	v := reflect.ValueOf(m)
 	if v.Kind() != reflect.Map {
 		panic(fmt.Sprintf("%#v is not a map", m))
 	}
-	keys := v.MapKeys()
-	s := make([]string, 0, len(keys))
-	for _, key := range keys {
-		s = append(s, key.String())
+	if v.Len() == 0 {
+		return nil
+	}
+	iter := v.MapRange()
+	s := make([]string, 0, v.Len())
+	for iter.Next() {
+		s = append(s, iter.Key().String())
 	}
 	sort.Strings(s)
 	return s
 }
 
+// stringValues returns the values of the given string-valued map in randomized map order.
+func stringValues(m interface{}) []string {
+	v := reflect.ValueOf(m)
+	if v.Kind() != reflect.Map {
+		panic(fmt.Sprintf("%#v is not a map", m))
+	}
+	if v.Len() == 0 {
+		return nil
+	}
+	iter := v.MapRange()
+	s := make([]string, 0, v.Len())
+	for iter.Next() {
+		s = append(s, iter.Value().String())
+	}
+	return s
+}
+
+// SortedStringValues returns the values of the given string-valued map in the ascending order.
+func SortedStringValues(m interface{}) []string {
+	s := stringValues(m)
+	sort.Strings(s)
+	return s
+}
+
+// SortedUniqueStringValues returns the values of the given string-valued map in the ascending order
+// with duplicates removed.
+func SortedUniqueStringValues(m interface{}) []string {
+	s := stringValues(m)
+	return SortedUniqueStrings(s)
+}
+
 // IndexList returns the index of the first occurrence of the given string in the list or -1
 func IndexList(s string, list []string) int {
 	for i, l := range list {
diff --git a/android/util_test.go b/android/util_test.go
index 09bec01..9b9253b 100644
--- a/android/util_test.go
+++ b/android/util_test.go
@@ -640,3 +640,117 @@
 		})
 	}
 }
+
+func TestSortedStringKeys(t *testing.T) {
+	testCases := []struct {
+		name     string
+		in       interface{}
+		expected []string
+	}{
+		{
+			name:     "nil",
+			in:       map[string]string(nil),
+			expected: nil,
+		},
+		{
+			name:     "empty",
+			in:       map[string]string{},
+			expected: nil,
+		},
+		{
+			name:     "simple",
+			in:       map[string]string{"a": "foo", "b": "bar"},
+			expected: []string{"a", "b"},
+		},
+		{
+			name:     "interface values",
+			in:       map[string]interface{}{"a": nil, "b": nil},
+			expected: []string{"a", "b"},
+		},
+	}
+
+	for _, tt := range testCases {
+		t.Run(tt.name, func(t *testing.T) {
+			got := SortedStringKeys(tt.in)
+			if g, w := got, tt.expected; !reflect.DeepEqual(g, w) {
+				t.Errorf("wanted %q, got %q", w, g)
+			}
+		})
+	}
+}
+
+func TestSortedStringValues(t *testing.T) {
+	testCases := []struct {
+		name     string
+		in       interface{}
+		expected []string
+	}{
+		{
+			name:     "nil",
+			in:       map[string]string(nil),
+			expected: nil,
+		},
+		{
+			name:     "empty",
+			in:       map[string]string{},
+			expected: nil,
+		},
+		{
+			name:     "simple",
+			in:       map[string]string{"foo": "a", "bar": "b"},
+			expected: []string{"a", "b"},
+		},
+		{
+			name:     "duplicates",
+			in:       map[string]string{"foo": "a", "bar": "b", "baz": "b"},
+			expected: []string{"a", "b", "b"},
+		},
+	}
+
+	for _, tt := range testCases {
+		t.Run(tt.name, func(t *testing.T) {
+			got := SortedStringValues(tt.in)
+			if g, w := got, tt.expected; !reflect.DeepEqual(g, w) {
+				t.Errorf("wanted %q, got %q", w, g)
+			}
+		})
+	}
+}
+
+func TestSortedUniqueStringValues(t *testing.T) {
+	testCases := []struct {
+		name     string
+		in       interface{}
+		expected []string
+	}{
+		{
+			name:     "nil",
+			in:       map[string]string(nil),
+			expected: nil,
+		},
+		{
+			name:     "empty",
+			in:       map[string]string{},
+			expected: nil,
+		},
+		{
+			name:     "simple",
+			in:       map[string]string{"foo": "a", "bar": "b"},
+			expected: []string{"a", "b"},
+		},
+		{
+			name:     "duplicates",
+			in:       map[string]string{"foo": "a", "bar": "b", "baz": "b"},
+			expected: []string{"a", "b"},
+		},
+	}
+
+	for _, tt := range testCases {
+		t.Run(tt.name, func(t *testing.T) {
+			got := SortedUniqueStringValues(tt.in)
+			if g, w := got, tt.expected; !reflect.DeepEqual(g, w) {
+				t.Errorf("wanted %q, got %q", w, g)
+			}
+		})
+	}
+}