title: Accessing the resource inside load/dump
body: <p>consider the following example</p>
  
  <pre><code>module DataMapper
    class Property
      class CustomType &lt; DataMapper::Property::Text
  
        def load(value)
          # do stuff and return formatted value 
        end
      end  
    end
  end
  
  Class A
    property :name, String
    property :value, CustomType
  end
  </code></pre>
  
  <p>now when I do <code>A.first</code> or <code>A.first.value</code> the <code>load</code> method gets executed, but the calculations that I need to do inside <code>load</code> is dependent on that instance's <code>name</code> property. So how do I get the context of this instance/resource(as referred inside source code) inside the load method ?</p>
  
  <p>Please let me know if the question is not clear yet !</p>