private void validateNumberFilesIsAtLeast(final int expected) {
    assertThat(numberOfFiles(dir)).as("Unexpected files: " + listFiles(dir))
        .isGreaterThanOrEqualTo(expected);
  }
Validates number of files under this.dir while ignoring this.dirOfDeletedFiles.
geode-core/src/integrationTest/java/org/apache/geode/internal/statistics/DiskSpaceLimitIntegrationTest.java