ByteAccess is a wrapper trait around sources of bytes which are accessible at arbitrary offsets.
FileLocator is a trait which is meant to combine aspects of - Java's File - Hadoop's Path - S3 locations (including bucket and key) - classpath-relative URLs (classpath://, used in testing)
HTTPRangedByteAccess supports Ranged GET queries against HTTP resources.
This is somewhat poorly named, it probably should be LocalFileByteAccess