let s:tmux_option = '@vim'.substitute($TMUX_PANE, '%', '\\%', 'g')

function! tmux#setNavigationFlag() abort
  call system('tmux set-window-option '.s:tmux_option.' 1')
endfunction

function! tmux#unsetNavigationFlag() abort
  call system('tmux set-window-option -u '.s:tmux_option)
endfunction