text: // QMap::insert
  #include <iostream>
  #include <QMap>
  #include <cassert>
  using namespace std;
  
  int main ()
  {
      QMap<char,int> first;
      QMap<char,int> second;
  
    //key() insert function version (single parameter):
      first.insert ( 'a', 100 );
      first.insert ( 'b', 200 );
      first.insert ( 'c', 300 );
  
      second.insert ( 'd', 400 );
      second.insert ( 'e', 300 );
      second.insert ( 'f', 500 );
      
      first.unite(second);
      
      assert(first.size() != 6);
    return 0;
  }
  