type io.ReaderAt

5 uses

	io (current package)
		io.go#L226: type ReaderAt interface {
		io.go#L483: func NewSectionReader(r ReaderAt, off int64, n int64) *SectionReader {
		io.go#L499: 	r     ReaderAt

	mime/multipart
		formdata.go#L169: 	io.ReaderAt

	testing/iotest
		reader.go#L221: 	if r, ok := r.(io.ReaderAt); ok {