code: func newAttribute(baseMT string) *design.AttributeDefinition {
  	var base design.DataType
  	if mt := design.Design.MediaTypeWithIdentifier(baseMT); mt != nil {
  		base = mt.Type
  	}
  	return &design.AttributeDefinition{Reference: base}
  }
docs: // newAttribute creates a new attribute definition using the media type with the given identifier
  // as base type.