Results 1 issues of Xinlu Tu

``` import org.apache.spark.sql.functions._ import com.databricks.spark.corenlp.functions._ val input = Seq( (1, "Stanford University is located in California. It is a great university"), (2, "") ).toDF("id", "text") input.withColumn("sentiment", sentiment($"text")).show() ``` **Error: org.apache.spark.SparkException:...