title: Array as value in json metadata properties send by Forge Derivative API
body: <p>I have a question about the structure of metadata properties extract from a translated IFC model. In the JSON I get all the properties for all objects and sometimes the value for a property is an array.
  For example in the picture, first line, the category of the object is not a string but an array.</p>
  
  <p>I don't know if it's a bug or something wrong in the IFC but when I open it in IFC viewer, values are only strings, there is no array. The current IFC is the urban house model that I found on the Autodesk website and often used in the forge demo.</p>
  
  <p>It's not a critical problem for me, I just check each time if the value is an array.
  I just wanted to know.</p>
  
  <p>Thanks</p>
  
  <p><a href="https://i.stack.imgur.com/FVUFR.jpg" rel="nofollow noreferrer">Example of array in properties values</a></p>
  
  <p>You can download IFC and Revit file</p>
  
  <p><a href="http://www.mediafire.com/file/t4s7p1w7rf4ejra/Urban_House.ifc/file" rel="nofollow noreferrer">Urban_House.ifc</a></p>
  
  <p><a href="http://www.mediafire.com/file/bhc4p6btqz3eity/Urban_House_2018.rvt/file" rel="nofollow noreferrer">Urban_House_2018.rvt</a></p>