sync IndexWriter.close()
implement SegmentWriteState.assertSegmentSuffix()
make 4.10 codec as default
implement PackedLongValuesBuilder.build()
implements PackedLongValuesBuilder.pack()
implement newNormMap()
implement PackedLongValues.iterator()
implement NormMap.add()
implement TermsWriter.pushTerm()
implement TermsWriter.writeBlocks()
implement TermsWriter.writeBlock()