Document arguments for custom display function

This is my custom code:

function computed_field_field_create_invoice_link_display($entity_field, $entity_type, $field) {
$display_output = 'test';
}

I get this message:

Notice: Undefined variable: entity_field_item in computed_field_field_create_invoice_link_display() (line 19 of /var/www/Anyjob-Portal/sites/all/modules/anyjob_settings/includes/create_invoice_link.inc).

I'm unclear what variables to pass to the function?