Robot won't drive. Help with "command based" programming

[Shaffer]

Here's our code, including our subsystem (cassie), our command (dothedrive), and our Robot file. It just won't drive no matter what we do. We have one joystick and mecanum drive.

public class cassie extends Subsystem
{

public SpeedController leftfront = RobotMap.cassieleftfront;
public SpeedController rightfront = RobotMap.cassierightfront;
public SpeedController leftrear = RobotMap.cassieleftrear;
public SpeedController rightrear = RobotMap.cassierightrear;
public RobotDrive wholecassie = RobotMap.cassiewholecassie;


public void initDefaultCommand()
{

}

public void takeJoyStickInput(Joystick joy1)
{
wholecassie.mecanumDrive_Cartesian(joy1.getRawAxis (1), joy1.getRawAxis(2), joy1.getRawAxis(0),0);

}

public void stop()
{
wholecassie.mecanumDrive_Cartesian(0, 0, 0,0);
}

}

public class dothedrive extends Command
{

public dothedrive()
{

requires(Robot.cassie);
}


protected void initialize()
{
}

protected void execute()
{
Robot.cassie.takeJoyStickInput(Robot.oi.getSidewin der());
}


protected boolean isFinished()
{
return false;
}

protected void end()
{
Robot.cassie.stop();

}


protected void interrupted()
{
}
}


public class Robot extends IterativeRobot
{

Command autonomousCommand;

public static OI oi;

public static cassie cassie;
public static lift lift;
public static grip grip;
public static vision vision;

public void robotInit()
{
RobotMap.init();

cassie = new cassie();
lift = new lift();
grip = new grip();
vision = new vision();


oi = new OI();
autonomousCommand = new AutonomousCommand();
}

public void disabledInit()
{
}

public void disabledPeriodic()
{
Scheduler.getInstance().run();
}

public void autonomousInit()
{
if (autonomousCommand != null) autonomousCommand.start();
}

public void autonomousPeriodic()
{
Scheduler.getInstance().run();
}

public void teleopInit() {

if (autonomousCommand != null) autonomousCommand.cancel();

}

public void teleopPeriodic()
{
Scheduler.getInstance().run();
wholecassie.dothedrive(); //this is the line that I'm confused on

}

public void testPeriodic()
{
LiveWindow.run();
}