title: In Java 8, how do I make a method reference to a method that takes no parameters and returns void?
body: <p>I have a bunch of methods with this signature:</p>
  
  <pre><code>public void sideEffects() {...}
  public void foo() {...}
  public void bar() {...}
  </code></pre>
  
  <p>(That is, they return void and take no parameters) And I'd like to be able to populate a List by doing something like this:</p>
  
  <pre><code>list.add(MyClass::sideEffects);
  list.add(MyClass::foo);
  list.add(MyClass::bar);
  </code></pre>
  
  <p>But, I'm unable to find a built in <code>@FunctionalInterface</code> in the <code>java.util.function</code> package that supports this signature.  Will I have to create my own <code>@FunctionalInterface</code> for this?</p>