title: Manipulate output in java8 stream
body: <p>Imagine we have list of 3 objects with minutes field as values: 5,5,7, 8</p>
  
  <pre><code>int sumOfFields = found.stream()
          .filter(abc -&gt; minutesLessThan5(abc.getMinutes())))
          .mapToInt(abc::getMinutes)
          .sum();
  
  // will return 10
  </code></pre>
  
  <p>But how can I change my output
  e.g. instead of getMinutes I want to return my own value e.g. 40</p>
  
  <pre><code>int sumOfFields = found.stream()
          .filter(abc -&gt; minutesLessThan5(abc.getMinutes())))
          .mapToInt(abc -&gt;abc.getMinutes() = 40)  //this is pseudo code what I try to achive
          .sum();
  
  // output should be 80.
  </code></pre>