Parsing error in neovim script

[iankuan]

I'm not familiar with this kind of command in vim script. Error msg is as follows:

tabstop=4"tabstop=4" [New File]
Cannot open file "tabstop=4"
Error detected while processing /home/uscc/dotfiles-yen/nvim/custom/basic.vim:
line  153:
E480: No match: foldmethod=marker