* @param array input array. All elements of argument array must be
* instances of {@link Step}
* @return an array of {@link Step}s
*/
private Expression[] toPredicatesArray(Object[] array) {
Expression predicatesArray[] = null;
if (array != null) {
predicatesArray = new Expression[array.length];
for (int i = 0; i < predicatesArray.length; i++) {
predicatesArray[i] = new ConvertingToJavaObjectExpressionWrapper(
(Expression) array[i]);