* Making the `tf.function` type system fully available:

    * `tf.types.experimental.TraceType` now allows custom tf.function inputs to declare Tensor decomposition and type casting support.

        bean.setRequiredCron(""); // Empty string passes NotNull but should pass CronExpression too
        violations = validator.validate(bean);
        assertTrue(violations.isEmpty());
    }

    // Test annotation composition
    public void test_composedAnnotation() {
        ComposedBean bean = new ComposedBean();
        bean.setComposedCron("invalid");

 *
 * @author Laurence Gonsalves
 * @author Harry Heymann
 * @since 2.0
 */
@GwtCompatible
public final class Suppliers {
  private Suppliers() {}

  /**
   * Returns a new supplier which is the composition of the provided function and supplier. In other
   * words, the new supplier's value will be computed by retrieving the value from {@code supplier},

 *
 * @author Laurence Gonsalves
 * @author Harry Heymann
 * @since 2.0
 */
@GwtCompatible
public final class Suppliers {
  private Suppliers() {}

  /**
   * Returns a new supplier which is the composition of the provided function and supplier. In other
   * words, the new supplier's value will be computed by retrieving the value from {@code supplier},