def close(end_time = ::Instana::Util.now_in_ms)

      if end_time.is_a?(Time)
        end_time = ::Instana::Util.time_to_ms(end_time)
      end

      @data[:d] = end_time - @data[:ts]
      self
    end
def close(end_time = ::Instana::Util.now_in_ms)

      if end_time.is_a?(Time)
        end_time = ::Instana::Util.time_to_ms(end_time)
      end

      @data[:d] = end_time - @data[:ts]
      self
    end
Closes out the span.  This difference between this and
 the finish method tells us how the tracing is being
 performed (with OpenTracing or Instana default)

 @param end_time [Time] custom end time, if not now
 @return [Span]