code: func NewPrincipal(name string, classification mb.MSPPrincipal_Classification) (*mb.MSPPrincipal, error) {
  	member1Role, err := proto.Marshal(&mb.MSPRole{Role: mb.MSPRole_MEMBER, MspIdentifier: name})
  	if err != nil {
  		return nil, errors.WithMessage(err, "Error marshal MSPRole")
  	}
  	return &mb.MSPPrincipal{
  		PrincipalClassification: classification,
  		Principal:               member1Role}, nil
  }
docs: // NewPrincipal creates a new MSPPrincipal