code: def convert_id(opts)
        opts = opts.clone
  
        [:id, :format, :destination_format, :mailbox ].each do |k|
          validate_param(opts, k, true)
        end
  
        req = build_soap! do |type, builder|
          if(type == :header)
          else
            builder.nbuild.ConvertId {|x|
              builder.nbuild.parent.default_namespace = @default_ns
              x.parent['DestinationFormat'] = opts[:destination_format].to_s.camel_case
              x.SourceIds { |x|
                x[NS_EWS_TYPES].AlternateId { |x|
                  x.parent['Format'] = opts[:format].to_s.camel_case
                  x.parent['Id'] = opts[:id]
                  x.parent['Mailbox'] = opts[:mailbox]
                }
              }
            }
          end
        end
        do_soap_request(req, response_class: EwsResponse)
      end
docs: Converts item and folder identifiers between formats.
   @see http://msdn.microsoft.com/en-us/library/bb799665.aspx
   @todo Needs to be finished