@Test
  public void testSplitLogFileMultipleRegions() throws IOException {
    LOG.info("testSplitLogFileMultipleRegions");
    generateWALs(1, 10, -1);
    splitAndCount(1, 10);
  }
Sets up a log splitter with a mock reader and writer. The mock reader generates a specified
number of edits spread across 5 regions. The mock writer optionally sleeps for each edit it is
fed. After the split is complete, verifies that the statistics show the correct number of edits
output into each region.
@param numFakeEdits   number of fake edits to push through pipeline
@param bufferSize     size of in-memory buffer
@param writerSlowness writer threads will sleep this many ms per edit
hbase-server/src/test/java/org/apache/hadoop/hbase/wal/TestWALSplit.java