code: @Override
      public DeleteCacheSubnetGroupResult deleteCacheSubnetGroup(DeleteCacheSubnetGroupRequest request) {
          request = beforeClientExecution(request);
          return executeDeleteCacheSubnetGroup(request);
      }
docs: <p>
  Deletes a cache subnet group.
  </p>
  <note>
  <p>
  You cannot delete a cache subnet group if it is associated with any clusters.
  </p>
  </note>
  
  @param deleteCacheSubnetGroupRequest
  Represents the input of a <code>DeleteCacheSubnetGroup</code> operation.
  @return Result of the DeleteCacheSubnetGroup operation returned by the service.
  @throws CacheSubnetGroupInUseException
  The requested cache subnet group is currently in use.
  @throws CacheSubnetGroupNotFoundException
  The requested cache subnet group name does not refer to an existing cache subnet group.
  @sample AmazonElastiCache.DeleteCacheSubnetGroup
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/elasticache-2015-02-02/DeleteCacheSubnetGroup"
  target="_top">AWS API Documentation</a>