public boolean isStatic() {
   return IterUtil.isStatic(_iterable);
 }
 public boolean hasFixedSize() {
   return IterUtil.hasFixedSize(_iterable);
 }
 /**
  * Return {@code size}, unless the nested iterable is smaller than {@code size}; in that case,
  * returns the iterable's size.
  */
 public int size() {
   return IterUtil.sizeOf(_iterable, _size);
 }
 public int size(int bound) {
   return IterUtil.sizeOf(_iterable, _size <= bound ? _size : bound);
 }
 public boolean isEmpty() {
   return (_size == 0) || IterUtil.isEmpty(_iterable);
 }