Nav component

nav.php

            <nav class="navbar navbar-default"> 
            <!-- toggle --> 
              <div class="navbar-header"> 
                <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-ex1-collapse"> 
                  <span class="sr-only">Toggle navigation</span> 
                  <span class="icon-bar"></span> 
                  <span class="icon-bar"></span> 
                  <span class="icon-bar"></span> 
                </button> 
              </div> 
              <!-- Collect the nav links, forms, and other content for toggling --> 
              <div class="collapse navbar-collapse navbar-ex1-collapse"> 
		<?php /* Primary navigation */
                wp_nav_menu( array(
                  'menu' => 'top_menu',
                  'depth' => 2,
                  'container' => false,
                  'menu_class' => 'nav navbar-nav',
                  //Process nav menu using our custom nav walker
                  'walker' => new wp_bootstrap_navwalker())
                );
                ?>
              </div>
            </nav>