///
/// Here is a simple example using integers:
///
+/// \code
/// EquivalenceClasses<int> EC;
/// EC.unionSets(1, 2); // insert 1, 2 into the same set
/// EC.insert(4); EC.insert(5); // insert 4, 5 into own sets
/// cerr << *MI << " "; // Print member.
/// cerr << "\n"; // Finish set.
/// }
+/// \endcode
///
/// This example prints:
/// 4