code: public static Collection split(Object self, Closure closure) {
          List accept = new ArrayList();
          List reject = new ArrayList();
          return split(closure, accept, reject, InvokerHelper.asIterator(self));
      }
docs: Splits all items into two lists based on the closure condition.
  The first list contains all items matching the closure expression.
  The second list all those that don't.
  
  @param self    an Object with an Iterator returning its values
  @param closure a closure condition
  @return a List whose first item is the accepted values and whose second item is the rejected values
  @since 1.6.0