func (s *Stack) less(r *Stack) bool {
	lStdlib := 0
	lPrivate := 0
	for _, c := range s.Calls {
		if c.IsStdlib {
			lStdlib++
		} else {
			lPrivate++
		}
	}
	rStdlib := 0
	rPrivate := 0
	for _, s := range r.Calls {
		if s.IsStdlib {
			rStdlib++
		} else {
			rPrivate++
		}
	}
	if lPrivate > rPrivate {
		return true
	}
	if lPrivate < rPrivate {
		return false
	}
	if lStdlib > rStdlib {
		return false
	}
	if lStdlib < rStdlib {
		return true
	}

	// Stack lengths are the same.
	for x := range s.Calls {
		if s.Calls[x].Func.Raw < r.Calls[x].Func.Raw {
			return true
		}
		if s.Calls[x].Func.Raw > r.Calls[x].Func.Raw {
			return true
		}
		if s.Calls[x].PkgSrc() < r.Calls[x].PkgSrc() {
			return true
		}
		if s.Calls[x].PkgSrc() > r.Calls[x].PkgSrc() {
			return true
		}
		if s.Calls[x].Line < r.Calls[x].Line {
			return true
		}
		if s.Calls[x].Line > r.Calls[x].Line {
			return true
		}
	}
	return false
}
func (s *Stack) less(r *Stack) bool {
	lStdlib := 0
	lPrivate := 0
	for _, c := range s.Calls {
		if c.IsStdlib {
			lStdlib++
		} else {
			lPrivate++
		}
	}
	rStdlib := 0
	rPrivate := 0
	for _, s := range r.Calls {
		if s.IsStdlib {
			rStdlib++
		} else {
			rPrivate++
		}
	}
	if lPrivate > rPrivate {
		return true
	}
	if lPrivate < rPrivate {
		return false
	}
	if lStdlib > rStdlib {
		return false
	}
	if lStdlib < rStdlib {
		return true
	}

	// Stack lengths are the same.
	for x := range s.Calls {
		if s.Calls[x].Func.Raw < r.Calls[x].Func.Raw {
			return true
		}
		if s.Calls[x].Func.Raw > r.Calls[x].Func.Raw {
			return true
		}
		if s.Calls[x].PkgSrc() < r.Calls[x].PkgSrc() {
			return true
		}
		if s.Calls[x].PkgSrc() > r.Calls[x].PkgSrc() {
			return true
		}
		if s.Calls[x].Line < r.Calls[x].Line {
			return true
		}
		if s.Calls[x].Line > r.Calls[x].Line {
			return true
		}
	}
	return false
}
// less compares two Stack, where the ones that are less are more
// important, so they come up front.
//
// A Stack with more private functions is 'less' so it is at the top.
// Inversely, a Stack with only public functions is 'more' so it is at the
// bottom.