Code Challenge "Throwing Exceptions"

public class GoKart {
  public static final int MAX_BARS = 8;
  private String mColor;
  private int mBarsCount;

  public GoKart(String color) {
    mColor = color;
    mBarsCount = 0;
  }

  public String getColor() {
    return mColor;
  }

  public void drive() {
    try {
      // This here calls the drive method from below
      drive(1); 
    } // Catch the error here {
         // print the error
    }
  }

  public void drive(int laps) {
   // Create a new variable and set the value to (mBarsCount - laps). 

   /* If you do that, the new value can be 
     checked first, before assigning it to mBarsCount. 
      If you don't, let's say if the value goes below 0, a bomb 
     will explode and after that, the exception will be thrown. You don't want that. 
     You want to throw the exception before the bomb goes off
  */ 

    if (theNewVariable < 0) {
      // throw exception
    }
    /* set mBarsCount to the value of the new variable. 
      This code here (after the if statement)
      won't get executed if the new value is below 0, 
      because then an exception will be thrown first
   */
  }

  public void charge() {
    while (!isFullyCharged()) {
      mBarsCount++;
    }
  }

  public boolean isBatteryEmpty() {
    return mBarsCount == 0;
  }

  public boolean isFullyCharged() {
    return mBarsCount == MAX_BARS;
  }

}