has the side effect of changing the plot settings on the map outside of Input as well as the plot_settings dictionary is effectively passed by reference. I think it would be better here to instead create a copy of the input map before adding it as an attribute on Input.
I don't know if this is really a bug per se, but altering the plot settings of the input magnetic field boundary map
https://github.com/dstansby/pfsspy/blob/26b6eac4ac86b677c997c4125fdf0ba0359efe15/pfsspy/input.py#L45-L49
has the side effect of changing the plot settings on the map outside of
Inputas well as theplot_settingsdictionary is effectively passed by reference. I think it would be better here to instead create a copy of the input map before adding it as an attribute onInput.