@Before
  public void setChunkSize() {
    // a random non-zero chunkSize in the range [2, 1024]
    chunkSize = random.nextInt(1023) + 2;
  }
Running for both regular and encrypted blobs
@return an array with both {@code false} and {@code true}.
ambry-router/src/test/java/com/github/ambry/router/ChunkFillTest.java