title: RubyMine: "Expression can be simplified" But how?
body: <p>How to simplify this expression?</p>
  
  <pre><code>m.immutable = params[:immutable] || false
  </code></pre>
  
  <p>RubyMine suggests: "Expression can be simplified. This inspection warns about redundant parts inside boolean function", but doesn't say what to do.</p>
  
  <p>The idea is to assign false if "immutable" parameter wasn't passed.</p>