Optional ReadonlyerrorWhy it failed, when it did.
ReadonlyidReadonlyinfoReadonlynameReadonlypeersReadonlyprogressReadonlyreceivedOptional ReadonlysizeUnknown until the swarm has sent the file list.
ReadonlyspeedBytes per second.
Readonlystate
A download as the user sees it. Sizes are bytes;
progressruns from 0 to 1.