# Functions
NewPullEngine creates an instance of a PullEngine with a certain sleep time between pull initiations.
NewPullEngineWithFilter creates an instance of a PullEngine with a certain sleep time between pull initiations, and uses the given filters when sending digests and responses.
SetDigestWaitTime sets the digest wait time.
SetRequestWaitTime sets the request wait time.
SetResponseWaitTime sets the response wait time.
# Structs
PullEngine is the component that actually invokes the pull algorithm with the help of the PullAdapter.
# Interfaces
PullAdapter is needed by the PullEngine in order to send messages to the remote PullEngine instances.
# Type aliases
DigestFilter filters digests to be sent to a remote peer that sent a hello or a request, based on its messages's context.