Zeppelin fails to compile function contains function as a parameter

case class TestClass(a: Int)

object TestClassBuilder {
  def get(a: Int) = TestClass(a)
}

def successToCompile()(filterFunc: (TestClass) => Boolean) {
  val rdd = sc.makeRDD(List(TestClass(1), TestClass(2)))
  rdd.filter(filterFunc)
}

def failToCompile(filterFunc: (TestClass) => Boolean) {
  val rdd = sc.makeRDD(List(TestClassBuilder.get(1), TestClassBuilder.get(2)))
  rdd.filter(filterFunc)
}