code: func (c *Corpus) EnumeratePermanodesByNodeTypes(fn func(camtypes.BlobMeta) bool, camliNodeTypes []string) {
  	for _, t := range camliNodeTypes {
  		set := c.permanodesSetByNodeType[t]
  		for br := range set {
  			if bm := c.blobs[br]; bm != nil {
  				if !fn(*bm) {
  					return
  				}
  			}
  		}
  	}
  }
docs: // EnumeratePermanodesByNodeTypes enumerates over all permanodes that might
  // have one of the provided camliNodeType values, calling fn for each. If fn returns false,
  // enumeration ends.