code: def _export(self, collection):
          
          fieldnames = collection[0].keys()
          faux_csv = ','.join(fieldnames) + '\r\n'
          for resource in collection:
              faux_csv += ','.join((str(x) for x in resource.values())) + '\r\n'
          response = make_response(faux_csv)
          response.mimetype = 'text/csv'
          return response
docs: Return a CSV of the resources in *collection*.
  
          :param list collection: A list of resources represented by dicts