remove dead code

Author: Davies Liu

sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMap.java

@@ -19,9 +19,8 @@
 
 import java.io.IOException;
 
-import com.google.common.annotations.VisibleForTesting;
-
 import org.apache.spark.SparkEnv;
+import org.apache.spark.memory.TaskMemoryManager;
 import org.apache.spark.sql.catalyst.InternalRow;
 import org.apache.spark.sql.catalyst.expressions.UnsafeProjection;
 import org.apache.spark.sql.catalyst.expressions.UnsafeRow;
@@ -31,7 +30,6 @@
 import org.apache.spark.unsafe.Platform;
 import org.apache.spark.unsafe.map.BytesToBytesMap;
 import org.apache.spark.unsafe.memory.MemoryLocation;
-import org.apache.spark.memory.TaskMemoryManager;
 
 /**
  * Unsafe-based HashMap for performing aggregations where the aggregated values are fixed-width.
@@ -218,11 +216,6 @@ public long getPeakMemoryUsedBytes() {
     return map.getPeakMemoryUsedBytes();
   }
 
-  @VisibleForTesting
-  public int getNumDataPages() {
-    return map.getNumDataPages();
-  }
-
   /**
    * Free the memory associated with this map. This is idempotent and can be called multiple times.
    */