function add($attribute)
    {
        if ($this->contains($attribute->type_uri)) {
            return new Auth_OpenID_AX_Error(
              sprintf("The attribute %s has already been requested",
                      $attribute->type_uri));
        }

        $this->requested_attributes[$attribute->type_uri] = $attribute;

        return true;
    }
function add($attribute)
    {
        if ($this->contains($attribute->type_uri)) {
            return new Auth_OpenID_AX_Error(
              sprintf("The attribute %s has already been requested",
                      $attribute->type_uri));
        }

        $this->requested_attributes[$attribute->type_uri] = $attribute;

        return true;
    }
function add ( $ attribute ) { if ( $ this -> contains ( $ attribute -> type_uri ) ) { return new Auth_OpenID_AX_Error ( sprintf ( "The attribute %s has already been requested" , $ attribute -> type_uri ) ) ; } $ this -> requested_attributes [ $ attribute -> type_uri ] = $ attribute ; return true ; }
Add an attribute to this attribute exchange request.

@param attribute: The attribute that is being requested
@return bool|Auth_OpenID_AX_Error
Add an attribute to this attribute exchange request .