@RestrictedApi(explanation = "Should only be called in tests", link = "",
      allowedOnPath = ".*/src/test/.*")
  boolean isStreamUnsupported() {
    return streamUnsupported;
  }
For tests only, returns whether the passed stream is supported
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/InputStreamBlockDistribution.java