public ActionStackSwap()
{
_StackOps = new StackChange[ 4 ];
_StackOps[ 0 ] = new StackPop( AVM1DataTypes.AVM_ANY ); // a
_StackOps[ 1 ] = new StackPop( AVM1DataTypes.AVM_ANY ); // b
_StackOps[ 2 ] = new StackPush( AVM1DataTypes.AVM_ANY ); // a
_StackOps[ 3 ] = new StackPush( AVM1DataTypes.AVM_ANY ); // b
}