Parsing images in feed json
Refactoring server response parsing: pass subvalues to lower-level parse functions, get upper level subvalues in upper level parse functions
Accessing Images and Videos of Media
Accessors for images in Images interface. MediaData interface. Rename MediaData struct to MediaDataInfo.
Create ImagesImpl through factory function
Implement width, height, url accessors in MediaData. Rename factory function of MediaImpl
Create MediaDataImpl through factory function
Accessors for videos on Videos interface