@Override
  public void clear() {
    Arrays.fill(a, 0, size, null);
    size = 0;
    assert !ASSERTS || size <= a.length;
  }
Grows this array list, ensuring that it can contain the given number of entries without
resizing, and in case enlarging it at least by a factor of two.

@param capacity the new minimum capacity for this array list.
geode-core/src/main/java/org/apache/geode/internal/cache/IdentityArrayList.java