<?xml version="1.0" encoding="utf-8"?>
  <android.support.design.widget.CoordinatorLayout
      xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
      android:layout_height="match_parent" android:fitsSystemWindows="true"
      tools:context=".MainActivity">
  
      <android.support.design.widget.AppBarLayout android:layout_height="wrap_content"
          android:layout_width="match_parent" android:theme="@style/AppTheme.AppBarOverlay">
  
          <android.support.v7.widget.Toolbar android:id="@+id/toolbar"
              android:layout_width="match_parent" android:layout_height="?attr/actionBarSize"
              android:background="?attr/colorPrimary" app:popupTheme="@style/AppTheme.PopupOverlay" />
  
      </android.support.design.widget.AppBarLayout>
  
      <include layout="@layout/content_main" />
  
      <android.support.design.widget.FloatingActionButton android:id="@+id/fab"
          android:layout_width="wrap_content" android:layout_height="wrap_content"
          android:layout_gravity="bottom|end" android:layout_margin="@dimen/fab_margin"
          android:src="@android:drawable/ic_dialog_email" />
  
  </android.support.design.widget.CoordinatorLayout>