function MaterialTab(tab, ctx) {
    if (tab) {
      if (ctx.element_.classList.contains(ctx.CssClasses_.MDL_JS_RIPPLE_EFFECT)) {
        var rippleContainer = document.createElement('span');
        rippleContainer.classList.add(ctx.CssClasses_.MDL_RIPPLE_CONTAINER);
        rippleContainer.classList.add(ctx.CssClasses_.MDL_JS_RIPPLE_EFFECT);
        var ripple = document.createElement('span');
        ripple.classList.add(ctx.CssClasses_.MDL_RIPPLE);
        rippleContainer.appendChild(ripple);
        tab.appendChild(rippleContainer);
      }

      tab.addEventListener('click', function(e) {
        e.preventDefault();
        ctx.resetTabState_();
        tab.classList.add(ctx.CssClasses_.ACTIVE_CLASS);
      });

    }
  }
Constructor for an individual tab.

@constructor
@param {Element} tab The HTML element for the tab.
@param {MaterialTabs} ctx The MaterialTabs object that owns the tab.