private void setFs() throws IOException {
    if (this.dfsCluster == null) {
      LOG.info("Skipping setting fs because dfsCluster is null");
      return;
    }
    FileSystem fs = this.dfsCluster.getFileSystem();
    CommonFSUtils.setFsDefault(this.conf, new Path(fs.getUri()));

    // re-enable this check with dfs
    conf.unset(CommonFSUtils.UNSAFE_STREAM_CAPABILITY_ENFORCE);
  }
Start a minidfscluster. Can only create one.
@param servers How many DNs to start.
@param hosts   hostnames DNs to run on.
@see #shutdownMiniDFSCluster()
@return The mini dfs cluster created.
hbase-server/src/test/java/org/apache/hadoop/hbase/HBaseTestingUtil.java