code: func NewCompressingTermVectorsFormat(formatName, segmentSuffix string,
  	compressionMode CompressionMode, chunkSize int) *CompressingTermVectorsFormat {
  	assert2(chunkSize >= 1, "chunkSize must be >= 1")
  	return &CompressingTermVectorsFormat{
  		formatName:      formatName,
  		segmentSuffix:   segmentSuffix,
  		compressionMode: compressionMode,
  		chunkSize:       chunkSize,
  	}
  }
docs: /*
  Create a new CompressingTermVectorsFormat
  
  formatName is the name of the format. This name will be used in the
  file formats to perform codec header checks.
  
  The compressionMode parameter allows you to choose between compression
  algorithms that have various compression and decompression speeds so
  that you can pick the one that best fits your indexing and searching
  throughput. You should never instantiate two CompressingTermVectorsFormats
  that have the same name but different CompressionModes.
  
  chunkSize is the minimum byte size of a chunk of documents. Highter
  values of chunkSize should improve the compression ratio but will
  require more memory at indexing time and might make document loading
  a little slower (depending on the size of your OS cache compared to
  the size of your index).
  */