Optional
initialValueFactory: (() => ValueType)Optional
initialThe name of the channel.
Return a new identical channel, optionally initialized from a checkpoint. Can be thought of as a "restoration" from a checkpoint which is a "snapshot" of the channel's state.
Optional
checkpoint: ValueTypeUpdate the channel's value with the given sequence of updates. The order of the updates in the sequence is arbitrary. This method is called by Pregel for all channels at the end of each step. If there are no updates, it is called with an empty sequence.
Raises InvalidUpdateError if the sequence of updates is invalid. Returns True if the channel was updated, False otherwise.
if the sequence of updates is invalid.
Stores the result of applying a binary operator to the current value and each new value.