A no-arg function that returns a tff.learning.Model. This method
must not capture TensorFlow tensors or variables and use them. The model
must be constructed entirely from scratch on each invocation, returning
the same pre-constructed model each call will result in an error.
a tff.templates.MeasuredProcess that broadcasts the
model weights on the server to the clients. It must support the signature
(input_values@SERVER -> output_values@CLIENT) and have empty state. If
set to default None, the server model is broadcast to the clients using
the default tff.federated_broadcast.
Controls the reduce loop function for
input dataset. An experimental reduce loop is used for simulation.