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)
+			}
+		})
+	}
+}