static ExtendedCell createCell(final int i, final byte[] value) {
    return createCell(format(i), value);
  }
HFile is Cell-based. It used to be byte arrays. Doing this test, pass Cells. All Cells
intentionally have same coordinates in all fields but row.
@param i     Integer to format as a row Key.
@param value Value to use
@return Created Cell.
hbase-diagnostics/src/main/java/org/apache/hadoop/hbase/HFilePerformanceEvaluation.java