title: How to test X509TrustManager subclass?
body: <p>I subclassed <code>javax.net.ssl.X509TrustManager</code> so I could use a private SSL cert. Now I am trying to write a JUnit test for my class, but the test cases keep giving me a null pointer exception.</p>
  
  <p><em>E.g.</em> my implementation of <code>checkClientTrusted()</code> is an empty method.  However, when I call that method with a (supposedly) valid instance of <code>X509Certificate[]</code> (and any sort of String for that matter), JUnit reports a <code>NullException</code> at that line of test code.  Any suggestions as to what I am missing?</p>