Create the classes:

public class A  {
  private int k() {
    return 2; 
  }     
}
public class B extends A {    
  public int k() {
    return 1; 
  }
  public int m() {
    return k();
  }  
  public int test() {
    return m();
  }
}

apply the pull up method refactoring to m 

public class A  {
  private int k() {
    return 2; 
  }
  public int m() {
    return k();
  }       
}
public class B extends A {    
  public int k() {
    return 1; 
  }
  public int test() {
    return m();
  }
}

The transformation changes behavior. After the transformation the test method returns 2 instead of 1