title: Test cases pass when run individually and fail when run together
body: <p>Showing error in class where i am trying to get the values of static ArrayList&lt;ArrayList&gt; adjacent_list_train=new ArrayList&lt;ArrayList&gt;();
  which is returning error like: java.lang.IndexOutOfBoundsException: Index 1 out of bounds for length 1. The issue is with the static variable?</p>
  <pre><code>class Node{
  
      
      static ArrayList&lt;ArrayList&lt;TrainVertices&gt;&gt; adjacent_list_train=new ArrayList&lt;ArrayList&lt;TrainVertices&gt;&gt;(); 
  public void CList(){
        //error thrown at the following line
      if(FlightEdges.size&gt;0) {
              if(!adjacent_list.isEmpty()) {
                  for(int i=0;i&lt;adjacent_list.size();i++) {
  //error line
                      ArrayList&lt;FlightEdges&gt; fe_al=adjacent_list.get(i);
  }
  }
  </code></pre>
  <p>As per my observation it is something about static variable being accessed in multiple test class.  As i am new to junit testing can you please tell what is wrong with the test class</p>