code: @Override
  	public IPAddressSection assignPrefixForSingleBlock() {
  		if(!isMultiple()) {
  			return this;
  		}
  		Integer newPrefix = getPrefixLengthForSingleBlock();
  		return newPrefix == null ? null : setPrefixLength(newPrefix, false);
  	}
docs: Returns the equivalent CIDR address section with a prefix length for which the subnet block for that prefix matches the range of values in this section.
  <p>
  If no such prefix length exists, returns null.
  <p>
  If this address represents just a single address, "this" is returned.
  
  @return