<div aura:id="toastId" class="slds-hide demo-only" style="height: 4rem;">
    <div class="slds-notify_container slds-is-relative">
        <div class="slds-notify slds-notify_toast slds-theme_success" role="alert">
            <span class="slds-assistive-text">success</span>
            <span class="slds-icon_container slds-icon-utility-success slds-m-right_small slds-no-flex slds-align-top" title="Description of icon when needed">
                                </span>
            <div class="slds-notify__content">
                <h2 class="slds-text-heading_small "> Toast message Line 1 <br/> toast message Line 2</h2>
            </div>
            <lightning:buttonIcon iconName="utility:close" variant="bare" class="slds-button_icon-inverse" onclick="{! c.closeToast}" />
        </div>
    </div>
</div>

handleToast : function(component, event, helper) {
     var toastComp = component.find("toastId");
     $A.util.removeClass(toastComp, 'slds-hide');
}

closeToast : function(component, event, helper) {
     var toastComp = component.find("toastId");
     $A.util.addClass(toastComp, 'slds-hide');
}