public int hash(final Currency c1,final Currency c2){
  return Math.min(c1.numericCode(),c2.numericCode()) * 1000 + Math.max(c1.numericCode(),c2.numericCode());
}

public int hash ( final Currency c1 , final Currency c2 ) { return Math . min ( c1 . numericCode ( ) , c2 . numericCode ( ) ) * 1000 + Math . max ( c1 . numericCode ( ) , c2 . numericCode ( ) ) ; }
creates a hash for two currencies .
