code: func (g *Graph) TrimLowFrequencyTags(tagCutoff int64) {
  	// Remove nodes with value <= total*nodeFraction
  	for _, n := range g.Nodes {
  		n.LabelTags = trimLowFreqTags(n.LabelTags, tagCutoff)
  		for s, nt := range n.NumericTags {
  			n.NumericTags[s] = trimLowFreqTags(nt, tagCutoff)
  		}
  	}
  }
docs: // TrimLowFrequencyTags removes tags that have less than
  // the specified weight.