Please see the following code sample

import javax.security.auth.kerberos.DelegationPermission;
...
        DelegationPermission d1 = new DelegationPermission("\"abc\"");
        DelegationPermission d2 = new DelegationPermission("\"abc\"");
        d1.equals(d2);

Execution result would be:

Exception in thread "main" java.lang.NullPointerException
at java.security.jgss/javax.security.auth.kerberos.DelegationPermission.equals(DelegationPermission.java:170)