simple pair class used for cache keys where the result is symmetric, e.g. similarity measures. Order o1 and o2 so that the results of the comparison is the same, regardless of the order of o1 and o2.
@author vijay
@param < T>
All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.