Sorry, my english is maybe not good, but my goal is not to get property, but to get ONLY favorite files. For example, i need to show last 25 favorite files sorted by createdAt in folder sites/Test/documentLibrary/Documents and that what you are describing will get all files but with property isFavorite and what i need to do if i need to show last 25 favorite files? I have to paging and count isFavorite. And if the user would like see next page, next 25 favorite files, what i need to do? The same process.
Therefore i'm looking for possibility how to get ONLY favorite files via API children or Search API.