lsp-jt.el fails to compile

[Jacobis9000]

On M-x package-install lsp-jt.el fails to compile:

lsp-jt.el:158:34:Warning: reference to free variable ‘java-tests’
lsp-jt.el:165:55:Warning: reference to free variable ‘node’
lsp-jt.el:172:24:Warning: reference to free variable ‘item’
lsp-jt.el:174:11:Warning: reference to free variable
    ‘treemacs-java-tests-closed-state’
lsp-jt.el:178:4:Warning: ‘:level’ called as a function
lsp-jt.el:254:32:Warning: reference to free variable ‘java-tests-list’
lsp-jt.el:404:1:Error: Wrong number of arguments: (1 . 1), 0lsp-jt.el:158:34:Warning: reference to free variable ‘java-tests’
lsp-jt.el:165:55:Warning: reference to free variable ‘node’
lsp-jt.el:172:24:Warning: reference to free variable ‘item’
lsp-jt.el:174:11:Warning: reference to free variable
    ‘treemacs-java-tests-closed-state’
lsp-jt.el:178:4:Warning: ‘:level’ called as a function
lsp-jt.el:254:32:Warning: reference to free variable ‘java-tests-list’
lsp-jt.el:404:1:Error: Wrong number of arguments: (1 . 1), 0