add scala doc

Author: xusliebana

src/main/scala/com/johnsnowlabs/nlp/HasMultipleInputAnnotationCols.scala

@@ -16,16 +16,20 @@
 
 package com.johnsnowlabs.nlp
 
-import com.johnsnowlabs.nlp.AnnotatorType.CHUNK
-import org.apache.spark.ml.param.{Params, StringArrayParam}
-import org.apache.spark.sql.types.StructType
-
+/**
+ * Trait  used to create annotators with input columns of variable length.
+ * */
 trait HasMultipleInputAnnotationCols extends HasInputAnnotationCols {
 
+  /** Annotator reference id. The Annotator type is the same for any of the input columns*/
   val inputAnnotatorType: String
 
   lazy override val inputAnnotatorTypes: Array[String] = getInputCols.map(_ =>inputAnnotatorType)
 
+  /**
+    * Columns that contain annotations necessary to run this annotator
+    * AnnotatorType is the same for all input columns in that annotator.
+    */
   override def  setInputCols(value: Array[String]): this.type = {
     set(inputCols, value)
   }

src/test/scala/com/johnsnowlabs/nlp/annotators/multipleannotations/MultiannotationsSpec.scala

@@ -1,9 +1,6 @@
 package com.johnsnowlabs.nlp.annotators.multipleannotations
 
-import com.johnsnowlabs.nlp.annotators.sbd.pragmatic.SentenceDetector
-import com.johnsnowlabs.nlp.{ContentProvider, DocumentAssembler, LightPipeline, RecursivePipeline, SparkAccessor}
-import com.johnsnowlabs.nlp.annotators.{TextMatcher, Tokenizer}
-import com.johnsnowlabs.nlp.util.io.ReadAs
+import com.johnsnowlabs.nlp.{DocumentAssembler, LightPipeline,SparkAccessor}
 import com.johnsnowlabs.tags.FastTest
 import org.apache.spark.ml.Pipeline
 import org.scalatest.flatspec.AnyFlatSpec
@@ -12,7 +9,7 @@ class MultiannotationsSpec  extends AnyFlatSpec {
   import SparkAccessor.spark.implicits._
 
   "An multiple anootator chunks" should "transform data " taggedAs FastTest in {
-    val data = SparkAccessor.spark.sparkContext.parallelize(Seq("Example text")).toDS().toDF("text")
+      val data = SparkAccessor.spark.sparkContext.parallelize(Seq("Example text")).toDS().toDF("text")
 
     val documentAssembler = new DocumentAssembler()
       .setInputCol("text")