title: writetime of cassandra row in spark
body: <p>i'm using spark with cassandra, and i want to select from my cassandra table the writeTime of my row. This is my request : </p>
  
  <pre><code>   val lines = sc.cassandraTable[(String, String, String, Long)](CASSANDRA_SCHEMA, table).select("a", "b", "c", "writeTime(d)").count()
  </code></pre>
  
  <p>but it display this error :</p>
  
  <pre><code>java.io.IOException: Column channal not found in table test.mytable
  </code></pre>
  
  <p>I've tried also this request </p>
  
  <pre><code>   val lines = sc.cassandraTable[(String, String, String, Long)](CASSANDRA_SCHEMA, table).select("a", "b", "c", WRITETIME("d")").count()
  </code></pre>
  
  <p>but it display this error : </p>
  
  <pre><code>&lt;console&gt;:25: error: not found: value WRITETIME
  </code></pre>
  
  <p>Please how can i get the writeTime of my row. 
  Thanks.</p>