title: How to know what classes are represented in return array from predict_proba in Scikit-learn
body: <p>I'm starting off with Scikit-learn... </p>
  
  <pre><code>&gt;&gt;&gt; import sklearn
  &gt;&gt;&gt; sklearn.__version__
  '0.13.1'
  &gt;&gt;&gt; from sklearn import svm
  &gt;&gt;&gt; model = svm.SVC(probability=True)
  &gt;&gt;&gt; X = [[1,2,3], [2,3,4]] # feature vectors
  &gt;&gt;&gt; Y = ['apple', 'orange'] # classes
  &gt;&gt;&gt; model.fit(X, Y)
  &gt;&gt;&gt; model.predict_proba([1,2,3])
  array([[ 0.39097541,  0.60902459]])
  </code></pre>
  
  <p>How do I know which class is supposed to be which?</p>