public void clear() {
    for (int row = 0; row < rows; row++) {
      for (int col = 0; col < columns; col++) {
        buffer[col][row].reset();
      }
    }
  }
Represents a buffer of the terminal screen for double-buffering.
hbase-hbtop/src/main/java/org/apache/hadoop/hbase/hbtop/terminal/impl/ScreenBuffer.java