code: func (b *Build) UnmarshalJSON(data []byte) error {
  	var ccBuild struct {
  		CreatedAt string `json:"created_at,omitempty"`
  		GUID      string `json:"guid,omitempty"`
  		Error     string `json:"error"`
  		Package   struct {
  			GUID string `json:"guid"`
  		} `json:"package"`
  		State   constant.BuildState `json:"state,omitempty"`
  		Droplet struct {
  			GUID string `json:"guid"`
  		} `json:"droplet"`
  	}
  
  	err := cloudcontroller.DecodeJSON(data, &ccBuild)
  	if err != nil {
  		return err
  	}
  
  	b.GUID = ccBuild.GUID
  	b.CreatedAt = ccBuild.CreatedAt
  	b.Error = ccBuild.Error
  	b.PackageGUID = ccBuild.Package.GUID
  	b.State = ccBuild.State
  	b.DropletGUID = ccBuild.Droplet.GUID
  
  	return nil
  }
docs: // UnmarshalJSON helps unmarshal a Cloud Controller Build response.