block) of the peer
    "presynced_headers" : n,              (numeric) The current height of header pre-synchronization with this peer, or -1 if no low-work sync is in progress
    "synced_headers" : n,                 (numeric) The last header we have in common with this peer
    "synced_blocks" : n,                  (numeric) The last block we have in common with this peer
    "inflight" : [                        (json array)
      n,                                  (numeric) The heights of blocks we're