resolve comments

sql-plugin/src/main/320/scala/org/apache/spark/sql/rapids/shims/v2/datetimeExpressions.scala

@@ -16,29 +16,41 @@
 
 package org.apache.spark.sql.rapids.shims.v2
 
+import java.util.concurrent.TimeUnit
+
 import ai.rapids.cudf.{ColumnVector, ColumnView, DType, Scalar}
-import com.nvidia.spark.rapids.{GpuColumnVector, GpuScalar}
+import com.nvidia.spark.rapids.{GpuColumnVector, GpuExpression, GpuScalar}
 import com.nvidia.spark.rapids.RapidsPluginImplicits._
+import com.nvidia.spark.rapids.shims.v2.ShimBinaryExpression
 
-import org.apache.spark.sql.catalyst.expressions.{Expression, TimeZoneAwareExpression}
-import org.apache.spark.sql.rapids.GpuTimeMath
+import org.apache.spark.sql.catalyst.expressions.{ExpectsInputTypes, Expression, TimeZoneAwareExpression}
 import org.apache.spark.sql.types._
 import org.apache.spark.sql.vectorized.ColumnarBatch
 import org.apache.spark.unsafe.types.CalendarInterval
 
 case class GpuTimeAdd(start: Expression,
                       interval: Expression,
                       timeZoneId: Option[String] = None)
-  extends GpuTimeMath(start, interval, timeZoneId) {
+  extends ShimBinaryExpression
+    with GpuExpression
+    with TimeZoneAwareExpression
+    with ExpectsInputTypes
+    with Serializable {
+
+  override def left: Expression = start
+  override def right: Expression = interval
+
+  override def toString: String = s"$left - $right"
+  override def sql: String = s"${left.sql} - ${right.sql}"
+
+  override lazy val resolved: Boolean = childrenResolved && checkInputDataTypes().isSuccess
+
+  val microSecondsInOneDay: Long = TimeUnit.DAYS.toMicros(1)
 
   override def withTimeZone(timeZoneId: String): TimeZoneAwareExpression = {
     copy(timeZoneId = Option(timeZoneId))
   }
 
-  override def intervalMath(us_s: Scalar, us: ColumnView): ColumnVector = {
-    us.add(us_s)
-  }
-
   override def inputTypes: Seq[AbstractDataType] =
     Seq(AnyTimestampType, TypeCollection(CalendarIntervalType, DayTimeIntervalType))
 
@@ -87,4 +99,8 @@ case class GpuTimeAdd(start: Expression,
       }
     }
   }
+
+  private def intervalMath(us_s: Scalar, us: ColumnView): ColumnVector = {
+    us.add(us_s)
+  }
 }