title: What kind of constructor is this, beginning with <T extends Drawable & DrawerToggle>?
body: <pre><code>&lt;T extends Drawable &amp; DrawerToggle&gt; ActionBarDrawerToggle(
          Activity activity, 
          Toolbar toolbar,
          DrawerLayout drawerLayout, 
          T slider,
          @StringRes int openDrawerContentDescRes,
          @StringRes int closeDrawerContentDescRes) {
  </code></pre>
  
  <p>During browsing source code of the class <a href="http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/5.0.2_r1/android/support/v7/app/ActionBarDrawerToggle.java" rel="nofollow noreferrer">ActionBarDrawerToggle.java</a>, I've found this constructor is declared without access specifier. Rather, its declaration starts with</p>
  
  <pre><code>&lt;T extends Drawable &amp; DrawerToggle&gt;
  </code></pre>
  
  <p>Please explain, what does it really mean?</p>