Wraps a handle that already supports RangeReadable (arbitrary
byte-range reads) with a Seekable capability: a single logical
stream whose read position can be jumped via seek(offset), rather than
requiring the caller to open a fresh stream per range.
seek must not be called while a read from the current position is still
in flight - like any seekable stream, seeking and reading are sequential,
not concurrent, operations on the same handle.
Wraps a handle that already supports RangeReadable (arbitrary byte-range reads) with a Seekable capability: a single logical stream whose read position can be jumped via
seek(offset), rather than requiring the caller to open a fresh stream per range.seekmust not be called while a read from the current position is still in flight - like any seekable stream, seeking and reading are sequential, not concurrent, operations on the same handle.