code: func (s *Struct) Field(name string) *Field {
  	f, ok := s.FieldOk(name)
  	if !ok {
  		panic("field not found")
  	}
  
  	return f
  }
docs: // Field returns a new Field struct that provides several high level functions
  // around a single struct field entity. It panics if the field is not found.