!HasLiftedArgs(*else_branch_function_def)) {
    return absl::OkStatus();
  }

  std::unique_ptr<FunctionBody> then_branch_function_body;
  TF_RETURN_IF_ERROR(FunctionDefToBodyHelper(
      *then_branch_function_def, AttrSlice(&then_branch_func.attr()), fld,
      &then_branch_function_body));

  std::unique_ptr<FunctionBody> else_branch_function_body;
  TF_RETURN_IF_ERROR(FunctionDefToBodyHelper(

  // 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