Divider.java

public class Divider {
  public int divide(int dividend, int divisor) {
    if (divisor == null) {
      throw new IllegalArgumentException("divisor must not be null");
    }
    if (dividend == null) {
      throw new IllegalArgumentException("dividend must not be null");
    }
    if (divisor == 0) {
      throw new IllegalArgumentException("divisor must not be 0");
    }
    return dividend / divisor;
  }
}