title: BeanUtils.copyProperties missing deeply nested variables?
body: <p>I'm using BeanUtils.copyProperties to copy the entire content of one object into another that inherit from it. </p>
  
  <p>Here is the context, the domain object from which the values are copied contains a Set of objects of custom type Xref. That custom type has an embedded class with various fields of various class types. </p>
  
  <p>For some reason one of the field from an object encapsulated within the embedded object does not get copied over. But most everything else I need do get copied over.</p>
  
  <p>With an example:</p>
  
  <pre><code>class Source {
  private Set&lt;Xref&gt; xref;
  ...
  }
  
  class Xref {
  ...
  public static class primaryKey {
  ...
  private MyObj obj;
  }
  }
  
  class MyObj {
  private Integer id;
  ...
  }
  </code></pre>
  
  <p>Using those names if I try to use BeanUtils.copyProperties to copy the content of a "Source" object into a "SourceExtended" object the value of source.xrefs.get(0).getPrimaryKey().getObj().getId() does not get copied over. 
  In the original object it has a value but in the target object it's null... </p>
  
  <p>Any idea why???</p>
  
  <p>Thank you.</p>