public static void notEmpty(Object[] array, String message) {
        if (ObjectUtils.isEmpty(array)) {
            throw new IllegalArgumentException(message);
        }
    }
Assert that an array has elements; that is, it must not be
{@code null} and must have at least one element.
<pre class="code">Assert.notEmpty(array, "The array must have elements");</pre>

@param array   the array to check
@param message the exception message to use if the assertion fails
@throws IllegalArgumentException if the object array is {@code null} or has no elements
src/main/java/spark/utils/Assert.java