def get_contacts(options = {})
      request_params = {}

      if !options[:updated_after].nil?
        warn '[warning] :updated_after is depracated in XeroGateway#get_contacts.  Use :modified_since'
        options[:modified_since] = options.delete(:updated_after)
      end

      request_params[:ContactID]     = options[:contact_id] if options[:contact_id]
      request_params[:ContactNumber] = options[:contact_number] if options[:contact_number]
      request_params[:order]         = options[:order] if options[:order]
      request_params[:ModifiedAfter] = options[:modified_since] if options[:modified_since]
      request_params[:where]         = options[:where] if options[:where]
      request_params[:page]          = options[:page]  if options[:page]

      response_xml = http_get(@client, "#{@xero_url}/Contacts", request_params)

      parse_response(response_xml, {:request_params => request_params}, {:request_signature => 'GET/contacts'})
    end
def get_contacts(options = {})
      request_params = {}

      if !options[:updated_after].nil?
        warn '[warning] :updated_after is depracated in XeroGateway#get_contacts.  Use :modified_since'
        options[:modified_since] = options.delete(:updated_after)
      end

      request_params[:ContactID]     = options[:contact_id] if options[:contact_id]
      request_params[:ContactNumber] = options[:contact_number] if options[:contact_number]
      request_params[:order]         = options[:order] if options[:order]
      request_params[:ModifiedAfter] = options[:modified_since] if options[:modified_since]
      request_params[:where]         = options[:where] if options[:where]
      request_params[:page]          = options[:page]  if options[:page]

      response_xml = http_get(@client, "#{@xero_url}/Contacts", request_params)

      parse_response(response_xml, {:request_params => request_params}, {:request_signature => 'GET/contacts'})
    end
The consumer key and secret here correspond to those provided
 to you by Xero inside the API Previewer.

 Retrieve all contacts from Xero

 Usage : get_contacts(:order => :name)
         get_contacts(:modified_since => Time)

 Note  : modified_since is in UTC format (i.e. Brisbane is UTC+10)