assertTrue(ex.getMessage().toLowerCase().contains("null"));
    }

    @Test
    @DisplayName("toByteArray returns empty when no mechanismToken")
    void toByteArrayWhenNull() {
        TestSpnegoToken t = new TestSpnegoToken();
        assertArrayEquals(new byte[0], t.toByteArray(), "empty array expected when mechanismToken is null");
    }

    @Test

    /**
     * {@return the identifier of the artifact}.
     */
    @Nonnull
    String getArtifactId();

    /**
     * Returns the classifier of the artifact.
     *
     * @return the classifier or an empty string if none, never {@code null}
     */
    @Nonnull
    String getClassifier();

    /**
     * {@return the specific version, range of versions, or meta-version of the artifact}.

   *
   * <p>If you only want to calculate the mean, use {@link #meanOf} instead of creating a {@link
   * Stats} instance.
   *
   * @throws IllegalStateException if the dataset is empty
   */
  public double mean() {
    checkState(count != 0);
    return mean;
  }

  /**
   * Returns the sum of the values.
   *
   * <h3>Non-finite values</h3>
   *

	d, err := config.getDriver(ctx, tier)
	if err != nil {
		return err
	}
	return checkWarmBackend(ctx, d)
}

// Empty returns if tier targets are empty
func (config *TierConfigMgr) Empty() bool {
	if config == nil {
		return true
	}
	return len(config.ListTiers()) == 0
}

// TierType returns the type of tier

	return nil
}

// Validate returns an error if key is empty
func (kv BatchJobKV) Validate() error {
	if kv.Key == "" {
		return BatchJobYamlErr{
			line: kv.line,
			col:  kv.col,
			msg:  "key can't be empty",
		}
	}
	return nil
}

// Empty indicates if kv is not set
func (kv BatchJobKV) Empty() bool {
	return kv.Key == "" && kv.Value == ""
}

     *
     * @return The group id of the unresolvable model, can be empty but never {@code null}.
     */
    public String getGroupId() {
        return groupId;
    }

    /**
     * Gets the artifact id of the unresolvable model.
     *
     * @return The artifact id of the unresolvable model, can be empty but never {@code null}.
     */
    public String getArtifactId() {

        generator.setCommandList(commands);
        assertTrue("Multiple commands should be settable", true);

        // Test with empty list
        generator.setCommandList(new ArrayList<>());
        assertTrue("Empty command list should be settable", true);

        // Test with single command
        generator.setCommandList(Collections.singletonList("single_command"));

  </module>

  <module name="SuppressWarningsFilter" />

  <!-- Checks Java files and forbids empty Javadoc comments. -->
  <!-- Although you can use the "JavadocStyle" rule for this, it considers Javadoc -->
  <!-- that only contains a "@return" line to be empty. -->
  <module name="RegexpMultiline">
    <property name="id" value="EmptyJavadoc" />
    <property name="format" value="\/\*[\s\*]*\*\/" />

     */
    public String getInput() {
        return input;
    }

    /**
     * Gets the input value or empty string if null.
     * @return the input value or empty string
     */
    public String getInputValue() {
        if (input == null) {
            return StringUtil.EMPTY;
        }
        return input;
    }

    /**
     * Checks if this item has been updated.

@SuppressWarnings("serial")
final class RegularImmutableBiMap<K, V> extends ImmutableBiMap<K, V> {
  static final RegularImmutableBiMap<Object, Object> EMPTY =
      new RegularImmutableBiMap<Object, Object>();

  private final transient ImmutableBiMap<V, K> inverse;

  @SuppressWarnings("unchecked") // used only for the empty map, which works for any types
  RegularImmutableBiMap() {
    super(new RegularImmutableMap<K, V>(new HashMap<K, V>()));