help creating new module in prestashop 1.6

[toanloau]

Hi everybody!

I am creating new module with prestashop 1.6.

i create options with code

$this->fields_options = array(
  'general' => array(
    ['title'] => $this->l('Carrier options'),                      // The title of the fieldset. If missing, default is 'Options'.
    ['top'] => $this->l('Text to display before the fieldset'),    // This text is display right above the first. Rarely used.
    ['image'] => 'url to icon',                                    // If missing, will use the default icon for the tab.
    ['description'] => $this->l('Display as description'),         // Displays an informational box above the fields.
    ['info'] => $this->l('Display as info'),                       // Displays an unstyled text above the fields.
    'fields' => array(                                             // The various option fields.
      'PS_CARRIER_DEFAULT' => array(                               // The aray is named after the option's ID. It must be the
                                                                   // same name as the value stored in the ps_configuration table.
        ['title'] => $this->l('Default carrier:'),                 // The name of the option.
        ['desc'] => $this->l('The default carrier used in shop'),  // The description of the option.
        ['cast'] => 'intval', 

In this line, ['image'] => 'url to icon',

i don't know where containt image to display .

Thanks advance!