title: lambda null pointer exception
body: <p>I am trying to filter and sort over a collection as follows:</p>
  
  <pre><code>List&lt;Tls201Appln&gt; appsFiltered = apps.stream()
                      .filter(x -&gt; x.getTls203ApplnAbstr().getApplnAbstractLg().toLowerCase().equals("en"))
                      .sorted((x1, x2) -&gt; x1.getApplnFilingDate().after(x2.getApplnFilingDate()) ? 1 : x1.getApplnFilingDate().before(x2.getApplnFilingDate())?-1:0)
                      .collect(Collectors.toList());
  </code></pre>
  
  <p>And it is throwing the following exception</p>
  
  <pre><code>java.lang.NullPointerException
      at it.jrc.tim.patstat.beans.PatstatExtractorAutumn2015.lambda$0(PatstatExtractorAutumn2015.java:402)
      at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:174)
      at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1374)
      at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
      at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
      at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
      at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
      at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
      at it.jrc.tim.patstat.beans.PatstatExtractorAutumn2015.findLastPatentNumber(PatstatExtractorAutumn2015.java:404)
  </code></pre>
  
  <p>applnFilingDate is a not null property on Tls201Appln. 
  Where is the null pointer coming from?</p>