title: Documenting reference class with roxygen2 R CMD check codoc mismatches warning
body: <p>I am trying to use roxygen2 to make documentation for a reference class object, but I keep getting this warning when I run R CMD check:</p>
  
  <pre><code>  S4 class codoc mismatches from documentation object 'myRefClass-class':
    Slots for class 'myRefClass'
    Code: .xData
    Inherited: .xData
    Docs: field1 field2
  </code></pre>
  
  <p>This is the ref class and roxygen2 block associated with above warning:</p>
  
  <pre><code>#' @title myRefClass class
  #' @description Description of myRefClass
  #' @import methods
  #' @exportClass myRefClass
  #' @slot field1 A character slot
  #' @slot field2 A numeric slot
  myRefClass&lt;-setRefClass(Class="myRefClass", 
                          fields=list(field1="character", 
                          field2="numeric"))
  </code></pre>
  
  <p>Here is the R documentation that was generated: </p>
  
  <blockquote>
    <p>myRefClass-class {testPackaging}  R Documentation myRefClass class</p>
    
    <p>Description</p>
    
    <p>Description of myRefClass</p>
    
    <p>Slots</p>
    
    <p>field1 
        A character slot</p>
    
    <p>field2 
        A numeric slot</p>
  </blockquote>
  
  <p>As to the documentation I could find, codoc is testing for consistency between my code and the documentation. From what I can tell, all the slot names are the same; perhaps I'm missing something. 
  Not sure if the documentation should have automatically marked this as a reference class, or if I should have indicated that in some way?
  I've found R documentation indicating that the slot, ".xData, is used to enable inheritance from abnormal types", but I am not sure why it applies to what I'm doing here or if I should be doing something with it.  </p>
  
  <p>I have tried a number of permutations of the roxygen tags and keeping close to the structure found here seems to be giving me the best result/least warnings from R CMD check: <a href="https://stackoverflow.com/questions/21532365/roxygen2-how-to-export-reference-class-generator/23497886#23497886">Roxygen2 - how to @export reference class generator?</a>
  I've been looking around the net for examples of how roxygen2 should be used with reference classes; maybe I'm looking in the wrong places -- I haven't had much luck.  </p>
  
  <p>I am using roxygen2 v 3.1.0 / RStudio Version 0.98.501 / R version 3.0.3 / OSX 10.9.2
  (note: tried upgrading to roxygen2 v 4.0 and it completely choked on the reference class to the point that no documentation was being generated at all)</p>
  
  <p>If some one knows of a CRAN package using roxygen2 and reference classes, so that I might see how it's done properly, or if some one knows what it is that I'm doing wrong, the help would be much appreciated. I am new at package building in R. </p>