Juris civilis initia et progressus. Ad leges XII. Tabularum brevis commentatio. Ex Ulpiani Fragmentorum Tituli XXIX. selectis notis illustrati. Gaii ex veteris jurisprudentiae Fragmentis Institutionu

In Law 4, Digest, On the constitution of the Prince.
The institution of the Thurians.

which that law sanctions, to which law an abrogation or derogation has been made; that which was sanctioned by a later law is considered neglected. Indeed, because that was finally law and ratified, as the Decemvirs say, which the people had last ordered. Therefore, if an old sanction had been abrogated by a new law, the old law yielded entirely to the new law; for the latest are the weightiest. Whence Modestinus says, αἱ μεταγενέστεραι διατάξεις the later ordinances ἰσχυρότεραι τῶν πρὸ αὐτῶν εἰσίν are stronger than those before them. Regarding the abrogation of ancient laws, a remarkable institution of the Thurians exists in Diodorus Siculus, book 12, and Demosthenes in a certain oration: that whoever wished to abrogate an old law should come forward into the assembly with a noose around his neck and advocate for a new one; if the people did not approve it, then his throat was broken with that same noose.

From Gellius, book 2, chapter 1.

What it means to "make the lawsuit one's own."

That this law was abrogated can be understood from the fact that it is established by laws concerning judges who "make the lawsuit their own" original: "litem suam facere" (Law 15, Digest, On Judgments). A judge is said to make the lawsuit his own by judging poorly because he is compelled to take on the cause of the person in whose favor he wrongly pronounced judgment and to defend it as if it were his own.

Law 1, Digest, On the Cornelian Law concerning assassins.
From Gellius, book 20, chapter 1.

But if any magistrate or judge of an inquiry had received money for a capital case so that someone would become a defendant by public law, Martianus writes that he is held by the Cornelian Law concerning assassins; its penalty is deportation to an island and the forfeiture of all property (Law 1, 3, of the same title).