code: func (s *Section) Subsection(name string) *Subsection {
  	for i := len(s.Subsections) - 1; i >= 0; i-- {
  		ss := s.Subsections[i]
  		if ss.IsName(name) {
  			return ss
  		}
  	}
  
  	ss := &Subsection{Name: name}
  	s.Subsections = append(s.Subsections, ss)
  	return ss
  }
docs: // Subsection returns a Subsection from the specified Section. If the
  // Subsection does not exists, new one is created and added to Section.