diff --git a/android/util_test.go b/android/util_test.go
index 32f92b4..dc8b908 100644
--- a/android/util_test.go
+++ b/android/util_test.go
@@ -118,3 +118,185 @@
 		}
 	}
 }
+
+func TestJoinWithPrefix(t *testing.T) {
+	testcases := []struct {
+		name     string
+		input    []string
+		expected string
+	}{
+		{
+			name:     "zero_inputs",
+			input:    []string{},
+			expected: "",
+		},
+		{
+			name:     "one_input",
+			input:    []string{"a"},
+			expected: "prefix:a",
+		},
+		{
+			name:     "two_inputs",
+			input:    []string{"a", "b"},
+			expected: "prefix:a prefix:b",
+		},
+	}
+
+	prefix := "prefix:"
+
+	for _, testCase := range testcases {
+		t.Run(testCase.name, func(t *testing.T) {
+			out := JoinWithPrefix(testCase.input, prefix)
+			if out != testCase.expected {
+				t.Errorf("incorrect output:")
+				t.Errorf("     input: %#v", testCase.input)
+				t.Errorf("    prefix: %#v", prefix)
+				t.Errorf("  expected: %#v", testCase.expected)
+				t.Errorf("       got: %#v", out)
+			}
+		})
+	}
+}
+
+func TestIndexList(t *testing.T) {
+	input := []string{"a", "b", "c"}
+
+	testcases := []struct {
+		key      string
+		expected int
+	}{
+		{
+			key:      "a",
+			expected: 0,
+		},
+		{
+			key:      "b",
+			expected: 1,
+		},
+		{
+			key:      "c",
+			expected: 2,
+		},
+		{
+			key:      "X",
+			expected: -1,
+		},
+	}
+
+	for _, testCase := range testcases {
+		t.Run(testCase.key, func(t *testing.T) {
+			out := IndexList(testCase.key, input)
+			if out != testCase.expected {
+				t.Errorf("incorrect output:")
+				t.Errorf("       key: %#v", testCase.key)
+				t.Errorf("     input: %#v", input)
+				t.Errorf("  expected: %#v", testCase.expected)
+				t.Errorf("       got: %#v", out)
+			}
+		})
+	}
+}
+
+func TestInList(t *testing.T) {
+	input := []string{"a"}
+
+	testcases := []struct {
+		key      string
+		expected bool
+	}{
+		{
+			key:      "a",
+			expected: true,
+		},
+		{
+			key:      "X",
+			expected: false,
+		},
+	}
+
+	for _, testCase := range testcases {
+		t.Run(testCase.key, func(t *testing.T) {
+			out := InList(testCase.key, input)
+			if out != testCase.expected {
+				t.Errorf("incorrect output:")
+				t.Errorf("       key: %#v", testCase.key)
+				t.Errorf("     input: %#v", input)
+				t.Errorf("  expected: %#v", testCase.expected)
+				t.Errorf("       got: %#v", out)
+			}
+		})
+	}
+}
+
+func TestPrefixInList(t *testing.T) {
+	prefixes := []string{"a", "b"}
+
+	testcases := []struct {
+		str      string
+		expected bool
+	}{
+		{
+			str:      "a-example",
+			expected: true,
+		},
+		{
+			str:      "b-example",
+			expected: true,
+		},
+		{
+			str:      "X-example",
+			expected: false,
+		},
+	}
+
+	for _, testCase := range testcases {
+		t.Run(testCase.str, func(t *testing.T) {
+			out := PrefixInList(testCase.str, prefixes)
+			if out != testCase.expected {
+				t.Errorf("incorrect output:")
+				t.Errorf("       str: %#v", testCase.str)
+				t.Errorf("  prefixes: %#v", prefixes)
+				t.Errorf("  expected: %#v", testCase.expected)
+				t.Errorf("       got: %#v", out)
+			}
+		})
+	}
+}
+
+func TestFilterList(t *testing.T) {
+	input := []string{"a", "b", "c", "c", "b", "d", "a"}
+	filter := []string{"a", "c"}
+	remainder, filtered := FilterList(input, filter)
+
+	expected := []string{"b", "b", "d"}
+	if !reflect.DeepEqual(remainder, expected) {
+		t.Errorf("incorrect remainder output:")
+		t.Errorf("     input: %#v", input)
+		t.Errorf("    filter: %#v", filter)
+		t.Errorf("  expected: %#v", expected)
+		t.Errorf("       got: %#v", remainder)
+	}
+
+	expected = []string{"a", "c", "c", "a"}
+	if !reflect.DeepEqual(filtered, expected) {
+		t.Errorf("incorrect filtered output:")
+		t.Errorf("     input: %#v", input)
+		t.Errorf("    filter: %#v", filter)
+		t.Errorf("  expected: %#v", expected)
+		t.Errorf("       got: %#v", filtered)
+	}
+}
+
+func TestRemoveListFromList(t *testing.T) {
+	input := []string{"a", "b", "c", "d", "a", "c", "d"}
+	filter := []string{"a", "c"}
+	expected := []string{"b", "d", "d"}
+	out := RemoveListFromList(input, filter)
+	if !reflect.DeepEqual(out, expected) {
+		t.Errorf("incorrect output:")
+		t.Errorf("     input: %#v", input)
+		t.Errorf("    filter: %#v", filter)
+		t.Errorf("  expected: %#v", expected)
+		t.Errorf("       got: %#v", out)
+	}
+}