code: public IPRangeNode findRange(IPRangeNode child) {
  
  	for (IPRangeNode c: this.list) {
  
  	    IPRangeNode result = c.findRange(child);
  
  	    if (result != null) return result;
  	}
  
  	return null;
      }
docs: performs a linear scan for unsorted lists
  
  @param child
  @return