# Variables
ErrHeightTooHigh is returned when the height is higher than the last block that the provider has.
ErrLightBlockNotFound is returned when a provider can't find the requested header (i.e.
ErrNoResponse is returned if the provider doesn't respond to the request in a gieven time.
# Structs
ErrBadLightBlock is returned when a provider returns an invalid light block.
# Interfaces
Provider provides information for the light client to sync (verification happens in the client).