return "z";
  }

  @Override
  protected String getValueNotInPopulatedMap() throws UnsupportedOperationException {
    return "26";
  }

  /** Helper assertion comparing two maps */
  private void assertMapsEqual(Map<?, ?> expected, Map<?, ?> map) {
    assertEquals(expected, map);
    assertEquals(expected.hashCode(), map.hashCode());

}

func (c *Content) Scan(src interface{}) error {
	var value Content
	str, ok := src.(string)
	if !ok {
		byt, ok := src.([]byte)
		if !ok {
			return errors.New("Embedded.Scan byte assertion failed")
		}
		if err := json.Unmarshal(byt, &value); err != nil {
			return err
		}
	} else {
		if err := json.Unmarshal([]byte(str), &value); err != nil {
			return err
		}
	}

 *
 * @param <K> the type of keys used by the maps under test
 * @param <V> the type of mapped values used the maps under test
 * @author George van den Driessche
 */
// TODO: Descriptive assertion messages, with hints as to probable fixes.
// TODO: Add another constructor parameter indicating whether the class under test is ordered, and
// check the order if so.
// TODO: Refactor to share code with SetTestBuilder etc.

    assertThat(e).hasMessageThat().contains("toString representation");
  }

  private static void assertErrorMessage(Throwable e, String message) {
    // TODO(kevinb): use a Truth assertion here
    if (!e.getMessage().contains(message)) {
      fail("expected <" + e.getMessage() + "> to contain <" + message + ">");
    }
  }

  /**

    return "z";
  }

  @Override
  protected String getValueNotInPopulatedMap() throws UnsupportedOperationException {
    return "26";
  }

  /** Helper assertion comparing two maps */
  private void assertMapsEqual(Map<?, ?> expected, Map<?, ?> map) {
    assertEquals(expected, map);
    assertEquals(expected.hashCode(), map.hashCode());

import org.junit.jupiter.params.provider.MethodSource;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.junit.jupiter.api.Assertions.assertTrue;

/**
 * Tests Artifact extraction, computation, and parent resolution functionality.
 */
@DisplayName("GAVUtils")

 *       other code to use these forms too. Only the most typically used JUnit assertion methods are
 *       defined this way, but enough to live with.
 *   <li>If you override {@link #setUp} or {@link #tearDown}, make sure to invoke {@code
 *       super.setUp} and {@code super.tearDown} within them. These methods are used to clear and
 *       check for thread assertion failures.

    // need a long enough string for the buffer to hit 0 remaining before the copy completes
    String string = Strings.repeat("0123456789", 100);
    StringBuilder b = new StringBuilder();
    // the main assertion of this test is here... the copy will fail if the buffer size goes down
    // each time it is not filled completely
    long copied = CharStreams.copy(newNonBufferFillingReader(new StringReader(string)), b);

    // need a long enough string for the buffer to hit 0 remaining before the copy completes
    String string = Strings.repeat("0123456789", 100);
    StringBuilder b = new StringBuilder();
    // the main assertion of this test is here... the copy will fail if the buffer size goes down
    // each time it is not filled completely
    long copied = CharStreams.copy(newNonBufferFillingReader(new StringReader(string)), b);

}
```

## 🏗️ Architecture & Design Patterns

### Core Design Principles
CoreLib follows a **utility-class pattern** where most functionality is exposed through static methods:

- **Assertion-based validation** - All methods validate inputs using `AssertionUtil.assertArgumentNotNull()` and `AssertionUtil.assertArgumentNotEmpty()`