boolean expected8 = true;
        doc.put("key8", expected8);
        assertEquals(expected8, DocumentUtil.getValue(doc, "key8", Boolean.class).booleanValue());
    }

    @Test
    public void test_getValue_with_null_map() {
        assertNull(DocumentUtil.getValue(null, "key", String.class));
        assertNull(DocumentUtil.getValue(null, "key", Integer.class));
    }

    @Test

    public void test_putAndGet() {
        dataStoreParams.put("key1", "value1");
        assertEquals("value1", dataStoreParams.get("key1"));

        dataStoreParams.put("key2", 123);
        assertEquals(123, dataStoreParams.get("key2"));

        dataStoreParams.put("key3", null);
        assertNull(dataStoreParams.get("key3"));
    }

    // Test get for non-existent key
    @Test
    public void test_getNonExistentKey() {

# Signing key for Gradle artifacts

Below is the public PGP key used to sign all Gradle artifacts.

The key ID is `E2F38302C8075E3D` and its fingerprint is `1BD97A6A154E7810EE0BC832E2F38302C8075E3D`.
You can also find the key in the [Gradle website](https://gradle.org/keys/) and on [public key servers](https://keys.openpgp.org/search?q=maven-publishing%40gradle.com).

## Verification instructions

### Importing the key

        // Test with whitespace around keys and values
        value = "  key1  =  value1  \n  key2=value2\n";
        paramMap = ParameterUtil.parse(value);
        assertEquals(2, paramMap.size());
        assertEquals("value1", paramMap.get("key1"));
        assertEquals("value2", paramMap.get("key2"));

        // Test with empty lines and mixed whitespace
        value = "key1=value1\n\n\t\nkey2=value2\n \n";

        String[] keys = entrySet.stream().map(Map.Entry::getKey).toArray(String[]::new);

        assertTrue("Should contain all keys", Arrays.asList(keys).contains("lang"));
        assertTrue("Should contain all keys", Arrays.asList(keys).contains("a_key"));
        assertTrue("Should contain all keys", Arrays.asList(keys).contains("b_key"));
        assertTrue("Should contain all keys", Arrays.asList(keys).contains("c_key"));

      while (same != 0xffffffff || diff != 0xffffffff) {
        int key1 = rand.nextInt();
        // flip input bit for key2
        int key2 = key1 ^ (1 << i);
        // get hashes
        int hash1 = function.hashInt(key1).asInt();
        int hash2 = function.hashInt(key2).asInt();
        // test whether the hash values have same output bits
        same |= ~(hash1 ^ hash2);

        pw.println("");
        pw.println("# A value comment");
        pw.println("key1 = val1");
        pw.println("");
        pw.println("# Another value comment");
        pw.println("key2 = ${key1}/foo");
        pw.println("");
        pw.println("# A third comment");
        pw.println("key3 = val3");
        pw.println("");

        MavenProperties props = new MavenProperties();

        StringBuilder buf = new StringBuilder();

        monitorTarget.append(buf, "key1", () -> "value1");
        buf.append(",");
        monitorTarget.append(buf, "key2", () -> 123);
        buf.append(",");
        monitorTarget.append(buf, "key3", () -> null);

        assertEquals("\"key1\":\"value1\",\"key2\":123,\"key3\":null", buf.toString());
    }

    // Test append with empty string
    @Test

    for (LoadingCache<Key, String> cache : caches()) {
      Key key1 = new Key(1);
      String value1 = key1.toString();
      Key key2 = new Key(2);
      String value2 = key2.toString();
      assertThat(cache.getUnchecked(key1)).isSameInstanceAs(value1);
      assertThat(cache.getUnchecked(key2)).isSameInstanceAs(value2);
      assertThat(cache.asMap().keySet()).isEqualTo(ImmutableSet.of(key1, key2));

    for (LoadingCache<Key, String> cache : caches()) {
      Key key1 = new Key(1);
      String value1 = key1.toString();
      Key key2 = new Key(2);
      String value2 = key2.toString();
      assertThat(cache.getUnchecked(key1)).isSameInstanceAs(value1);
      assertThat(cache.getUnchecked(key2)).isSameInstanceAs(value2);
      assertThat(cache.asMap().keySet()).isEqualTo(ImmutableSet.of(key1, key2));