code: func (mp *MergePolicyImpl) SetNoCFSRatio(noCFSRatio float64) {
  	assert2(noCFSRatio >= 0 && noCFSRatio <= 1, fmt.Sprintf(
  		"noCFSRatio must be 0.0 to 1.0 inclusive; got %v", noCFSRatio))
  	mp.noCFSRatio = noCFSRatio
  }
docs: /*
  If a merged segment will be more than this percentage of the total
  size of the index, leave the segment as non-compound file even if
  compound file is enabled. Set to 1.0 to always use CFS regardless or
  merge size.
  */