Before:
root
 |-- a: struct (nullable = true)
 |    |-- b: string (nullable = true)
 |    |-- c: array (nullable = true)
 |    |    |-- element: struct (containsNull = true)
 |    |    |    |-- d: array (nullable = true)
 |    |    |    |    |-- element: string (containsNull = true)
 |    |    |    |-- e: string (nullable = true)