@Override
      public void remove() {
        if (last == -1) {
          throw new IllegalStateException();
        }
        IdentityArrayList.this.remove(last);
        /*
         * If the last operation was a next(), we are removing an element *before* us, and we must
         * decrease pos correspondingly.
         */
        if (last < pos) {
          pos--;
        }
        last = -1;
      }
Adds elements to this type-specific list using optimized system calls.

@param index the index at which to add elements.
@param a the array containing the elements.
@param offset the offset of the first element to add.
@param length the number of elements to add.
geode-core/src/main/java/org/apache/geode/internal/cache/IdentityArrayList.java