if (successors != null) {
      checkState(successors.add(node));
    }
  }

  private static <T> @Nullable T getReference(@Nullable Reference<T> reference) {
    return (reference == null) ? null : reference.get();
  }

/**
 * An immutable object that may contain a non-null reference to another object. Each instance of
 * this type either contains a non-null reference, or contains nothing (in which case we say that
 * the reference is "absent"); it is never said to "contain {@code null}".
 *
 * <p>A non-null {@code Optional<T>} reference can be used as a replacement for a nullable {@code T}

        () -> equalsTester.addEqualityGroup(reference, equalObject1, null));
  }

  /** Test adding null equal object yields error */
  public void testAddNullEqualObject() {
    assertThrows(
        NullPointerException.class,
        () -> equalsTester.addEqualityGroup(reference, (Object[]) null));
  }

  /**
   * Test adding objects only by addEqualityGroup, with no reference object specified in the
   * constructor.
   */

    private String message;

    private String reference;

    private List<ExceptionSummary> children;

    public ExceptionSummary(Throwable exception, String message, String reference) {
        this(exception, message, reference, null);
    }

    public ExceptionSummary(Throwable exception, String message, String reference, List<ExceptionSummary> children) {
        this.exception = exception;

	// check relations
	relations := []Relation{
		{
			Name: "Account", Type: schema.HasOne, Schema: "User", FieldSchema: "Account",
			References: []Reference{{"ID", "User", "UserID", "Account", "", true}},
		},
		{
			Name: "Pets", Type: schema.HasMany, Schema: "User", FieldSchema: "Pet",
			References: []Reference{{"ID", "User", "UserID", "Pet", "", true}},
		},
		{
			Name: "Toys", Type: schema.HasMany, Schema: "User", FieldSchema: "Toy",

class Components(BaseModelWithConfig):
    schemas: dict[str, Schema | Reference] | None = None
    responses: dict[str, Response | Reference] | None = None
    parameters: dict[str, Parameter | Reference] | None = None
    examples: dict[str, Example | Reference] | None = None
    requestBodies: dict[str, RequestBody | Reference] | None = None
    headers: dict[str, Header | Reference] | None = None

  public static <T> T verifyNotNull(@Nullable T reference) {
    return verifyNotNull(reference, "expected a non-null reference");
  }

  /**
   * Ensures that {@code reference} is non-null, throwing a {@code VerifyException} with a custom
   * message otherwise.
   *
   * @param errorMessageTemplate a template for the exception message should the check fail. The

### 2. Code

Provide code to help us reproduce your issues using one of the following options:

#### Option A: Reference colab notebooks

1)  Reference [TensorFlow Model Colab](https://colab.research.google.com/gist/ymodak/e96a4270b953201d5362c61c1e8b78aa/tensorflow-datasets.ipynb?authuser=1): Demonstrate how to build your TF model.

    @DisplayName("toByteArray returns mechanismToken reference when present")
    void toByteArrayReturnsToken() throws IOException {
        TestSpnegoToken t = new TestSpnegoToken();
        byte[] raw = new byte[] { 11, 12, 13 };
        t.parse(raw);
        // Current behavior of test impl: returns same reference
        assertSame(raw, t.toByteArray(), "should return the same reference as mechanismToken");
    }

    @Test

    if (adjacentNodes != null) {
      checkState(adjacentNodes.add(node));
    }
  }

  private static <T> @Nullable T getReference(@Nullable Reference<T> reference) {
    return (reference == null) ? null : reference.get();
  }