TensorFlow Federated 0.50.0

Release 0.50.0

Major Features and Improvements

• Added client learning rate measurements to
  tff.learning.algorithms.build_weighted_fed_avg_with_optimizer_schedule
• Added support for streaming federated structure values to the C++
  RemoteExecutor.
• Added a C++ executor for executing TF graphs using TF2 DTensor APIs when
  layout information is specified for input parameters or variables in the
  graph.

Breaking Changes

• Deprecated the following API, Python execution is deprecated instead use CPP
  execution:
  • tff.framework.local_executor_factory
  • tff.framework.remote_executor_factory_from_stubs
  • tff.framework.DataExecutor
  • tff.framework.EagerTFExecutor
• Removed the following API, Python execution is deprecated instead use CPP
  execution:
  • tff.backends.native.create_local_python_execution_context
  • `tff.backends.native.create_remote_python_execution_context
  • tff.framework.remote_executor_factory
• Remove the executors_errors module from the tff.framework API, use
  tff.framework.RetryableError instead.

Bug Fixes

• Fixed potential lifetime issue in C++ RemoteExecutor
• Enabled and fixed python type annotations in many packages.
• Fixed one-off error in evaluation criteria in training program logic.