title: Get called class name in Another class
body: <p>we have one class</p>
  
  <pre><code>class A
  {
      // I am using class B here
     public function whatever()
     {
        $class_b = new B;
        $class_b-&gt;show_caller();
     }
  }
  </code></pre>
  
  <p>and other</p>
  
  <pre><code>class B
  {
      public function show_caller()
      {
          // show me the caller class (should output "A")
      }
  
  }
  </code></pre>
  
  <p>I need to get the caller class name.
  P.S. Inheritance is not an option!</p>