title: how to exclude whole property if they are null from Modelmapper
body: <p>Does ModelMapper(<a href="http://modelmapper.org/" rel="noreferrer">http://modelmapper.org/</a>) support what exclude property? If the value is null.</p>
  
  <p>I just found PropertyMap out. but It is a constraint to me.
  because I have to describe a specific property that I want. </p>
  
  <p>Like this.</p>
  
  <pre><code>ModelMapper modelMapper = new ModelMapper();
  modelMapper.addMappings(new PropertyMap&lt;TestObject, TestObject&gt;() {
      @Override
      protected void configure() {
          when(Conditions.isNull()).skip().setName(source.getName());
          when(Conditions.isNull()).skip().set...(source.get...());
          when(Conditions.isNull()).skip().set...(source.get...());
          when(Conditions.isNull()).skip().set...(source.get...());
          when(Conditions.isNull()).skip().set...(source.get...());
          when(Conditions.isNull()).skip().set...(source.get...());
      }
  });
  </code></pre>
  
  <p>In my case, I have a lot of property and verbose. 
  How to exclude mapping property if they are null from all them.
  Is there more comfortable solution?</p>
  
  <p>thanks.</p>