public static Class<?>[] toClass(Object... array) {
        if (array == null) {
            return null;
        } else if (array.length == 0) {
            return ArrayUtils.EMPTY_CLASS_ARRAY;
        }
        Class<?>[] classes = new Class[array.length];
        for (int i = 0; i < array.length; i++) {
            classes[i] = array[i] == null ? null : array[i].getClass();
        }
        return classes;
    }
<p>Converts an array of {@code Object} in to an array of {@code Class} objects.
If any of these objects is null, a null element will be inserted into the array.</p>

<p>This method returns {@code null} for a {@code null} input array.</p>

@param array an {@code Object} array
@return a {@code Class} array, {@code null} if null array input
@since 2.4
android/android_framework/base/src/main/java/lang3/ClassUtils.java