/usr/share/zsh/functions/Zftp/zfclose is in zsh-common 5.4.2-3ubuntu3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | # function zfclose {
[[ $curcontext = :zf* ]] || local curcontext=:zfclose
zftp close
# }
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