title: Using kneighbors() with Knn
body: <p>Problem here:
  I am using a knn via a pipeline:</p>
  <pre><code>knn_pipe = Pipeline([
      ('scaler', StandardScaler()),
      ('knn', KNeighborsClassifier(n_neighbors=10))
  ])
  
  knn_pipe.fit(X_tr, y_tr)
  </code></pre>
  <p>And I want to use this one with that fit to use NearestNeighbors</p>
  <p>Problem: this neirestneighbors needs to be compiled via a fit but I am unable to use the one above, don't know how to extract it from the pipeline.</p>
  <p>Any idea?</p>
  <p>Many thanks!</p>