code: @DoesServiceRequest
      public final void downloadRange(final long offset, final Long length, final OutputStream outStream,
              final AccessCondition accessCondition, FileRequestOptions options, OperationContext opContext)
              throws StorageException {
          if (offset < 0 || (length != null && length <= 0)) {
              throw new IndexOutOfBoundsException();
          }
  
          if (opContext == null) {
              opContext = new OperationContext();
          }
  
          opContext.initialize();
          options = FileRequestOptions.populateAndApplyDefaults(options, this.fileServiceClient);
  
          ExecutionEngine.executeWithRetry(this.fileServiceClient, this,
                  this.downloadToStreamImpl(offset, length, outStream, accessCondition, options, opContext),
                  options.getRetryPolicyFactory(), opContext);
      }
docs: Downloads the contents of a file to a stream using the specified request options and operation context.
  
  @param offset
  A <code>long</code> which represents the offset to use as the starting point for the source.
  @param length
  A <code>Long</code> which represents the number of bytes to read or <code>null</code>.
  @param outStream
  An <code>{@link OutputStream}</code> object that represents the target stream.
  @param accessCondition
  An {@link AccessCondition} object that represents the access conditions for the file.
  @param options
  A {@link FileRequestOptions} object that specifies any additional options for the request. Specifying
  <code>null</code> will use the default request options from the associated service client (
  {@link CloudFileClient}).
  @param opContext
  An {@link OperationContext} object that represents the context for the current operation. This object
  is used to track requests to the storage service, and to provide additional runtime information about
  the operation.
  @throws StorageException
  If a storage service error occurred.