The code block below contains an error. It is intended to create a Scala UDF assessPerformanceUDF() and apply it to the integer column customerSatisfaction in DataFrame storesDF. Identify the error.

Code block:

val assessPerformanceUDF = udf((customerSatisfaction: Int) => 
  customerSatisfaction match {
    case x if x < 20 => 1
    case x if x > 80 => 3
    case _ => 2
  }
)
storesDF.withColumn("result", assessPerformanceUDF(col("customerSatisfaction")))
```_

val assessPerformanceUDF = udf((customerSatisfaction: Int) => 
  customerSatisfaction match {
    case x if x < 20 => 1
    case x if x > 80 => 3
    case _ => 2
  }
)
storesDF.withColumn("result", assessPerformanceUDF(col("customerSatisfaction")))
```_