@Nullable
  @Override
  public TerminalSize getTerminalSize() {
    TerminalSize terminalSize = super.getTerminalSize();
    if (terminalSize == null) {
      return null;
    }
    updatePageSize(terminalSize);
    return terminalSize;
  }
The screen that provides a dynamic real-time view for the HBase metrics. This shows the metric
{@link Summary} and the metric {@link Record}s. The summary and the metrics are updated
periodically (3 seconds by default).
hbase-hbtop/src/main/java/org/apache/hadoop/hbase/hbtop/screen/top/TopScreenView.java