some tests
- get rid of functions just return standard http response
- maybe dont return one http.response instead return slice of responses and body binder api
- add tests
- use httptest to with serving static to mock Accept-Range
- go routine
- thread number benchmarking to auto determine number of threads
- check server support with header and resp body length
- take http client interface from user
- chunks and threads should be independent
- placeholder media downloads for examples
- simple proxy as example