title: Converting row values into a column array in spark dataframe
body: <p>I am working on spark dataframes and I need to do a group by of a column and convert the column values of grouped rows into an array of elements as new column.
  Example :</p>
  
  <pre><code>Input:
  
  employee | Address
  ------------------
  Micheal  |  NY
  Micheal  |  NJ
  
  Output:
  
  employee | Address
  ------------------
  Micheal  | (NY,NJ)
  </code></pre>
  
  <p>Any help is highly appreciated.!</p>