Read this: The Brazilian federal constitution states that the power to enter into treaties is vested in the president and that such treaties must be approved by Congress (articles 84, clause VIII, and 49, clause I). In practice, this has been interpreted as meaning that the executive branch is free to negotiate and sign a treaty, but its ratification by the president is contingent upon the prior approval of Congress. Additionally, the Federal Supreme Court has ruled that, following ratification and entry into force, a treaty must be incorporated into domestic law by means of a presidential decree published in the federal register in order to be valid in Brazil and applicable by the Brazilian authorities.

What Brazilian institution has ruled that a treaty must be incorporated into domestic law by means of a presidential decree?
What is the answer? (If it cannot be answered, return "unanswerable")
the Federal Supreme Court