Matt Fishman

I just realized that usually I wouldn't expect any variational parameters to be passed to `productMPS` so maybe it could just be marked with `@non_differentiable`. But I guess you might...

Probably the easiest way to catch this error would be to first do the assignment naively as-is, and then loop through the blocks of the ITensor that exist after the...

Note we can just add a call to `checkflux` which checks that all blocks have the same flux and errors if not.

Maybe better to use dispatch here to ensure there isn't any runtime overhead, for example: ```julia @propagate_inbounds @inline function _getindex(T::Tensor{

Actually it looks like the test was supposed to give an error, but now the error is different so just needs to be updated to `DimensionMismatch` from `MethodError`: https://github.com/ITensor/ITensors.jl/blob/f55d05fa4075521e88eacb648d6012a49ef3aa80/test/empty.jl#L49.

Not sure what the status of `T = emptyITensor(); T[i=>1,i'=>1] = 1.0` will be, I would be in support of adding that (but that doesn't need to be done now).

Also it would be helpful to have options for different levels of verbosity when printing QN objects.

Hi Sujay, Thanks for all your work on this and sorry for the slow response. Over all the PR looks good. My main concern is that `replacebond!` is not the...

Hi Sujay, Copying the existing tests and adding `nsites = 3` should be sufficient, thanks. The Schwinger model would be a great example to add to the `examples/` directory. Yes,...

Also see discussion in PR #569.