Ingests value 'val' given the expected type type_spec.
This function is invoked on Python call arguments and/or their constituents
to translate them into a form that can be used in the given context. This
is performed in the process of handling a computation's __call__(), while
bundling arguments together, and prior to calling invoke().
An object that represents the value to ingest in the given context.
The tff.Type of the value represented by this object.
The result of ingestion, which is context-dependent.
Prior to calling invoke, the argument arg or its constituents must have
been ingested by the context by calling ingest.
The computation being invoked. The Python type of comp expected
here (e.g., pb.Computation. ComputationImpl, or other) may depend on
the context. It is the responsibility of the concrete implementation of
this interface to verify that the type of comp matches what the
context is expecting.
The optional argument of the call (possibly an argument tuple with a
nested structure), or None if no argument was supplied. Computations
accept arguments in a variety of forms, but those are first ingested by
calling ingest() above, then bundled together into a single object
before calling invoke() in the given context.
The result of invocation, which is context-dependent.