/**
 * Call a method (over RPC) on the bound OpenERP model.
 *
 * @param {String} method name of the method to call
 * @param {Array} [args] positional arguments
 * @param {Object} [kwargs] keyword arguments
 * @param {Object} [options] additional options for the rpc() method
 * @returns {jQuery.Deferred<>} call result
 */
call: function (method, args, kwargs, options) {
    args = args || [];
    kwargs = kwargs || {};
    if (!_.isArray(args)) {
        // call(method, kwargs)
        kwargs = args;
        args = [];
    }
    var call_kw = '/web/dataset/call_kw/' + this.name + '/' + method;
    return session.rpc(call_kw, {
        model: this.name,
        method: method,
        args: args,
        kwargs: kwargs
    }, options);
},

var compose_model = new Model('mail.compose.message');
return compose_model.call('create', [msg, {default_parent_id: options.parent_id}])
    .then(function(id){
        return compose_model.call('send_mail_action', [id, {}]);
    });