title: Change schema of dataframe to other schema
body: <p>I hava dataframe that looks like this</p>
  <pre><code>df.printSchema()
  
  root
   |-- id: integer (nullable = true)
   |-- data: struct (nullable = true)
   |    |-- foo01 string (nullable = true)
   |    |-- bar01 string (nullable = true)
   |    |-- foo02 string (nullable = true)
   |    |-- bar02 string (nullable = true)
  </code></pre>
  <p>and I want to transform it to</p>
  <pre><code>root
   |-- id: integer (nullable = true)
   |-- foo: struct (nullable = true)
   |    |-- foo01 string (nullable = true)
   |    |-- foo02 string (nullable = true)
   |-- bar: struct (nullable = true)
   |    |-- bar01 string (nullable = true)
   |    |-- bar02 string (nullable = true)
  </code></pre>
  <p>What is the best way to go about this?</p>