cmf.minimal_twist (reviewed)

The minimal twist of a newform $f$ is the twist $g$ of $f$ whose label is lexicographically minimal among all twists of $f$ that are both twist minimal and have minimal character $\chi$.

A key feature of the minimal twist $g$ (and more generally, of any twist minimal $g$ of level $N$ and minimal character $\chi$) is that for any character $\psi$, the level $M$ of the twist $g\otimes\psi$ can be computed as $M={\rm lcm}(N,{\rm cond}(\psi){\rm cond}(\chi\psi))$.