// depends on an op with static output shape like tf.Const.
  absl::StatusOr<mlir::FunctionType> InferLibFunctionType(
      const FunctionBody& fbody);

  // Extracts arg and ret nodes from FunctionBody.
  void GetArgsAndRetsFromFunctionBody(
      const FunctionBody& fbody,
      absl::InlinedVector<OutputTensor, 4>* arg_nodes,
      absl::InlinedVector<OutputTensor, 4>* ret_nodes,

<p>
A function declaration binds an identifier, the <i>function name</i>,
to a function.
</p>

<pre class="ebnf">
FunctionDecl = "func" FunctionName Signature [ FunctionBody ] .
FunctionName = identifier .
FunctionBody = Block .
</pre>

<p>
If the function's <a href="#Function_types">signature</a> declares
result parameters, the function body's statement list must end in