nmap <Leader><Leader> <Plug>BookmarkToggle
nmap <Leader>i <Plug>BookmarkAnnotate
nmap <Leader>a <Plug>BookmarkShowAll
nmap <Leader>j <Plug>BookmarkNext
nmap <Leader>k <Plug>BookmarkPrev 
nmap <Leader>c <Plug>BookmarkClear 
nmap <Leader>x <Plug>BookmarkClearAll
nmap <Leader>kk <Plug>BookmarkMoveUp
nmap <Leader>jj <Plug>BookmarkMoveDown