code: @Override
  	public boolean isSinglePrefixBlock() {
  		Integer networkPrefixLength = getNetworkPrefixLength();
  		if(networkPrefixLength == null) {
  			return false;
  		}
  		return containsSinglePrefixBlock(networkPrefixLength);
  	}
docs: Returns whether the division grouping range matches the block of values for its prefix length.
  In other words, returns true if and only if it has a prefix length and it has just a single prefix.