public long getBytesPerSec() {
    long elapsed = (EnvironmentEdgeManager.currentTime() - startTime) / 1000;
    if (elapsed == 0) {
      return bytesRead;
    } else {
      return bytesRead / elapsed;
    }
  }
Getter for the read-rate from this stream, since creation. Calculated as
bytesRead/elapsedTimeSinceStart.
@return Read rate, in bytes/sec.
hbase-common/src/main/java/org/apache/hadoop/hbase/io/hadoopbackport/ThrottledInputStream.java