title: java.lang.LinkageError: loader constraint violation in interface itable initialization
body: <p>When I am executing my code, I am getting the below error.
  This is happening after I upgraded from JDK 1.6 to 1.8 </p>
  
  <pre><code>java.lang.LinkageError: loader constraint violation in interface itable initialization: when resolving method "javax.security.auth.kerberos.JavaxSecurityAuthKerberosAccessImpl.keyTabTakeSnapshot(Ljavax/security/auth/kerberos/KeyTab;)Lsun/security/krb5/internal/ktab/KeyTab;" the class loader (instance of org/powermock/core/classloader/MockClassLoader) of the current class, javax/security/auth/kerberos/JavaxSecurityAuthKerberosAccessImpl, and the class loader (instance of &lt;bootloader&gt;) for interface sun/security/krb5/JavaxSecurityAuthKerberosAccess have different Class objects for the type javax/security/auth/kerberos/KeyTab used in the signature
      at javax.security.auth.kerberos.KeyTab.&lt;clinit&gt;(KeyTab.java:100)
      at java.lang.Class.forName0(Native Method)
      at java.lang.Class.forName(Class.java:264)
      at org.apache.hadoop.security.UserGroupInformation.&lt;clinit&gt;(UserGroupInformation.java:609)
  </code></pre>