code: public boolean isChildOf(GeometryIndex parentIndex, GeometryIndex childIndex) {
  		return delegate.isChildOf(toDelegate(parentIndex), toDelegate(childIndex));
  	}
docs: Checks to see if a given index is the child of another index.
  
  @param parentIndex The so-called parent index.
  @param childIndex The so-called child index.
  @return Is the second index really a child of the first index?