title: Java "target type of lambda conversion must be an interface"
body: <p>I'm trying to use lambdas and streams in java but I'm quite new to it.
  I got this error in IntelliJ "target type of lambda conversion must be an interface" when I try to make a lambda expression</p>
  
  <pre><code>List&lt;Callable&lt;SomeClass&gt;&gt; callList = prgll.stream()
                                            .map(p-&gt;(()-&gt;{return p.funct();} )) &lt;--- Here I get error
                                            .collect(Collectors.toList());
  </code></pre>
  
  <p>Am I doing something wrong?</p>