#ifndef DATA_H_
#define DATA_H_

class List;
class Data {
public:
    Data();
    Data(int aID);
    virtual ~Data();
    virtual int getID();
    virtual void setID(int aID);
private:
    int ID;
    List *listOne;
    List *listTwo;
};

#endif /* DATA_H_ */

#include "Data.h"
#include "List.h"

Data::Data() {
    listOne = new List();
    listTwo = new List();
    Data::ID = 0;
}

Data::Data(int aID) {
    Data::listOne = new List();
    Data::listTwo = new List();
    Data::ID = aID;
}

Data::~Data() {
    delete(listOne);
    delete(listTwo);
}

int Data::getID() {
    return Data::ID;
}

void Data::setID(int aID) {
    Data::ID = ID;
}

..Data.cpp: In constructor 'Data::Data()':
..Data.cpp:12:23: error: invalid use of incomplete type 'class List'
  listOne = new List();
                       ^
In file included from ..Data.cpp:8:0:
..Data.h:11:7: note: forward declaration of 'class List'
 class List;
       ^
..Data.cpp:13:22: error: invalid use of incomplete type 'class List'
  listTwo = new List();
                      ^
In file included from ..Data.cpp:8:0:
..Data.h:11:7: note: forward declaration of 'class List'
 class List;
       ^
..Data.cpp: In constructor 'Data::Data(int)':
..Data.cpp:18:29: error: invalid use of incomplete type 'class List'
  Data::listOne = new List();
                             ^
In file included from ..Data.cpp:8:0:
..Data.h:11:7: note: forward declaration of 'class List'
 class List;
       ^
..Data.cpp:19:28: error: invalid use of incomplete type 'class List'
  Data::listTwo = new List();
                            ^
In file included from ..Data.cpp:8:0:
..Data.h:11:7: note: forward declaration of 'class List'
 class List;
       ^
..Data.cpp: In destructor 'virtual Data::~Data()':
..Data.cpp:24:18: warning: possible problem detected in invocation of delete operator: [-Wdelete-incomplete]
  delete(listOne);
                  ^
..Data.cpp:24:18: warning: invalid use of incomplete type 'class List'
In file included from ..Data.cpp:8:0:
..Data.h:11:7: note: forward declaration of 'class List'
 class List;
       ^
..Data.cpp:24:18: note: neither the destructor nor the class-specific operator delete will be called, even if they are declared when the class is defined
  delete(listOne);
                  ^
..Data.cpp:25:17: warning: possible problem detected in invocation of delete operator: [-Wdelete-incomplete]
  delete(listTwo);
                 ^
..Data.cpp:25:17: warning: invalid use of incomplete type 'class List'
In file included from ..Data.cpp:8:0:
..Data.h:11:7: note: forward declaration of 'class List'
 class List;
       ^
..Data.cpp:25:17: note: neither the destructor nor the class-specific operator delete will be called, even if they are declared when the class is defined
  delete(listTwo);

..Data.h:25:2: error: 'List' does not name a type
  List *cpubursts;
  ^
..Data.h:26:2: error: 'List' does not name a type
  List *iobursts;