private File createFile(final String name, final int mainId, final int childId) {
    File file = new File(dir, name + "-" + leftPad(valueOf(mainId), 2, "0") + "-"
        + leftPad(valueOf(childId), 2, "0") + ".gfs");
    return file;
  }
Validates number of files under this.dir while ignoring this.dirOfDeletedFiles.
geode-core/src/integrationTest/java/org/apache/geode/internal/statistics/DiskSpaceLimitIntegrationTest.java