Timestream.lookup

Timestream.lookup(key)

Return a Timestream looking up the value of self for each key.

For each non-null point in the key timestream, returns the value

from self at that time and associated with that key. Returns null

if the key is null or if there is no value computed for that key

at the corresponding time.

Parameters:

key (Arg)

The foreign key to lookup. This must match the type of the keys in self.