What is wrong with this code for the section on Method Signatures?

Here is my code, but it won't compile. Can any one help me? The question asks me to make a new method called "drive" that accepts no arguments and increments by one.

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

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

public String getColor() { return mColor; }

public drive() { return lap += 1;
}

mLaps = drive();

public void drive(int laps) { // Other driving code omitted for clarity purposes mBarsCount -= laps; }

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

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

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

}

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

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

  public String getColor() {
    return mColor;
  }

  public drive() {
    return lap += 1;  
  }

mLaps = drive();

  public void drive(int laps) {
    // Other driving code omitted for clarity purposes
    mBarsCount -= laps;
  }



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

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

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

}