I am trying to run some tests. Namely 

```
assertDataFrameEquals(etalon, agg)

```

on 2 dataframes. But get the following error

```
ScalaTestFailureLocation
Expected StructField(value1,ArrayType(StringType,true),false)
Actual   StructField(value2,ArrayType(StringType,true),true)

```

One df is created from a list

```
val etalon= spark.sparkContext.parallelize(data).toDF()

```

The other is calculated from some input files.

If value2 was a String or some other such type, I could do 

```
etalon.na.fill()

```

on it. But this doesn't work on arrays. What else can I do?