Hello guys.
Salesforce gives the possibility to connect GoogleDrive, Share point so on as external data sources and extend Files with this "third-party" data sources as additional "connected sources". As I understood from documentation we can do so for any external file storage but not only for predefined list of storages. 
I've started to develop custom solution to integrate our file archive as an external data source(based on DataSource.Connection and DataSource.Provider extension) and faced a problem - I can't find instruction or explanation what I have to implement to add this external data storage to files as "connected resources".
Our external files work in separate tab and are synced well but only as external objects, not files.
Could anybody advise some documentation or hint where to find details/examples of custom "Files connect" implementation?

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