code: func findMatchingSymbol(objSyms []*objSymbol, ns nodes) *objSymbol {
  	for _, n := range ns {
  		for _, o := range objSyms {
  			if filepath.Base(o.sym.File) == n.info.objfile &&
  				o.sym.Start <= n.info.address-o.base &&
  				n.info.address-o.base <= o.sym.End {
  				return o
  			}
  		}
  	}
  	return nil
  }
docs: // findMatchingSymbol looks for the symbol that corresponds to a set
  // of samples, by comparing their addresses.