title: Scala Specs2 Matchers with "aka" doesn't work
body: <p>Scala Specs2 matcher that looks like this (for example):</p>
  
  <pre><code>  def haveSizeOf(size: Int): Matcher[ProductElement] = { 
      productElement: ProductElement =&gt;
      val sizeOfproductElement = productElement.size
      sizeOfproductElement aka "size of product element"
    } ^^ beEqualTo(size)
  </code></pre>
  
  <p>And it's execution in the code:</p>
  
  <pre><code>updatedProductElement must haveSizeOf(1)
  </code></pre>
  
  <p>Throws error:</p>
  
  <blockquote>
    <p>java.lang.Exception:
    'org.specs2.matcher.ThrownExpectations$$anon$1@6a3b7968'</p>
    
    <p>is not equal to </p>
    
    <p>'1'</p>
  </blockquote>
  
  <p>What should i have done differently?</p>
  
  <p><strong>Edit:</strong>
   If <code>aka</code> removed, test passing successfully:</p>
  
  <pre><code>   def haveSizeOf(size: Int): Matcher[ProductElement] = { 
          productElement: ProductElement =&gt;
          productElement.size
        } ^^ beEqualTo(size)
  </code></pre>