public MultiMapImpl(int maxCapacity){
  _maxCapacity=maxCapacity;
  int size=8;
  _keys=(K[])new Object[size];
  _values=(List<V>[])new List[size];
  _size=0;
}

public MultiMapImpl ( int maxCapacity ) { _maxCapacity = maxCapacity ; int size = 8 ; _keys = ( K [ ] ) new Object [ size ] ; _values = ( List < V > [ ] ) new List [ size ] ; _size = 0 ; }
create the hash map impl with a specific capacity .
