title: AWS Comprehend custom classification job output has more rows than input
body: <p>I have used AWS Comprehend to train an NLP model. The prediction on the test set runs successfully, but the output file has more rows than the input:</p>
  
  <p>input:  1000 rows</p>
  
  <p>output: 2082 rows</p>
  
  <p>Output looks like this:</p>
  
  <pre><code>predictions.json &lt;...&gt;
  {"File": "test.csv", "Line": "0", "Classes": [{"Name": "No", "Score": 0.7022}, {"Name": "Yes", "Score": 0.2892}, {"Name": "tag", "Score": 0.0086}]}
  {"File": "test.csv", "Line": "1", "Classes": [{"Name": "No", "Score": 0.6252}, {"Name": "Yes", "Score": 0.3747}, {"Name": "tag", "Score": 0.0001}]}
  {"File": "test.csv", "Line": "2", "Classes": [{"Name": "No", "Score": 0.9295}, {"Name": "Yes", "Score": 0.0705}, {"Name": "tag", "Score": 0.0}]}
  {"File": "test.csv", "Line": "3", "Classes": [{"Name": "No", "Score": 0.5247}, {"Name": "Yes", "Score": 0.4753}, {"Name": "tag", "Score": 0.0}]}
  ...
  {"File": "test.csv", "Line": "2080", "Classes": [{"Name": "No", "Score": 0.8528}, {"Name": "Yes", "Score": 0.1471}, {"Name": "tag", "Score": 0.0001}]}
  {"File": "test.csv", "Line": "2081", "Classes": [{"Name": "No", "Score": 0.5318}, {"Name": "Yes", "Score": 0.4682}, {"Name": "tag", "Score": 0.0}]}
  </code></pre>
  
  <p>Can anyone help me on how to use the output?</p>