title: using an entryset in a lambdastream
body: <p>I need to create a map where the Integer corresponds with the maintenance periods a car has scheduled and with the set being the cars that have that amount of periods.</p>
  <p>I'm getting these errors:
  Lambda expression's signature does not match the signature of the functional interface method get()</p>
  <p>AND</p>
  <p>The method getValue() is undefined for
  the type T
  - The method size() is undefined for the
  type T
  I'm using eclipse if thats of any help.
  Any help would be greatly appreciated.</p>
  <pre><code>private Map&lt;Integer, Set&lt;Auto&gt;&gt;  summarize(Map&lt;String, List&lt;Maintenance&gt;&gt; carMaintenanceMap) {
        //carMap is &lt;String, Car&gt;
          Map&lt;Integer, Set&lt;Car&gt;&gt; map = new HashMap&lt;&gt;() ;
          map = carMaintenanceMap.entrySet().stream()
                  
                  .collect(Collectors.toMap(
                          entry -&gt; 
                          
                          entry.getValue(), val -&gt; val.size() ,
                          
                          
                          entry -&gt; 
                          
                          entry.getKey(), k -&gt; this.carMap.entrySet().stream()
                           .filter(entry -&gt; entry.getKey().equals(k)µ
                             .collect(Collectors.toSet())
                          
                          
                            ));
      }
  </code></pre>