### Eigenvalues of matrices of Laurent polynomials

Say that I have a matrix whose entries are univariate Laurent polynomials over complex numbers. In that case, I can substitute the variable for non-zero complex numbers to obtain an ordinary complex matrix. My question is the following: what the correct way to obtain the eigenvalues of the resulting complex matrix? My first guess was to do something like the following which just throws a NotImplementedError:

```
sage: R = LaurentPolynomialRing(CC, 'x')
sage: x = R.gens()[0]
sage: m = matrix([[x]])
sage: m.subs({x: 2}).eigenvalues()
```