Determines whether there is more data to read.
bool empty() @property;
bool empty() shared @property;
This property is empty iff no more elements are in the internal
close() has been called. Once the channel is empty,
subsequent calls to
consumeAll will throw an
Note that relying on the return value to determine whether another
element can be read is only safe in a single-reader scenario. Use
tryConsumeOne in a multiple-reader scenario instead.