Execute (Setup):
  let g:vimtex_imaps_leader = ';'
  let g:vimtex_imaps_disabled = ['a']
  call vimtex#imaps#add_map({'lhs' : 'vv', 'rhs' : '\vec{'})
  call vimtex#imaps#add_map({
    \ 'lhs' : 'test',
    \ 'rhs' : 'tested',
    \ 'leader' : '',
    \ 'wrapper' : 'vimtex#imaps#wrap_trivial',
    \})
  call vimtex#imaps#add_map({
    \ 'lhs' : 'cool',
    \ 'rhs' : '\item',
    \ 'leader' : '',
    \ 'wrapper' : 'vimtex#imaps#wrap_environment',
    \ 'context' : ["itemize", "enumerate"],
    \})
  silent! VimtexReload

Given tex (Minimal tex file):
  \documentclass{minimal}
  \begin{document}
  \end{document}

Do (imaps: some default maps):
  jo$;; ;b$

Expect tex (Verify):
  \documentclass{minimal}
  \begin{document}
  $; \beta$
  \end{document}

Do (imaps: imaps_disabled):
  jo$a = ;a$

Expect tex (Verify):
  \documentclass{minimal}
  \begin{document}
  $a = ;a$
  \end{document}

Do (imaps: imaps#add_map test -> tested):
  jotest

Expect tex (Verify):
  \documentclass{minimal}
  \begin{document}
  tested
  \end{document}

Do (imaps: imaps#add_map ;vv -> \vec{f}):
  jo$|f| = ;vvf}\cdot;vvf}$ --- ;vv

Expect tex (Verify):
  \documentclass{minimal}
  \begin{document}
  $|f| = \vec{f}\cdot\vec{f}$ --- ;vv
  \end{document}

Do (imaps: imaps#add_map cool -> \item):
  jocool\<cr>
  \begin{itemize}\<cr>
  cool\<cr>
  \end{itemize}

Expect tex (Verify):
  \documentclass{minimal}
  \begin{document}
  cool
  \begin{itemize}
    \item
  \end{itemize}
  \end{document}