A code is over 2000 lines full of folds. I select a certain block in Visual mode to which I would like to start writing. However, things around the block, such as folds, hinder my writing, and I accidentally tend to modify them. Currently, I avoid such mistakes by writing the block in a separate vim. It is not a real solution, and it gets awkward with too many vim's open.
How can I hide everything except the block in folds?