I became annoyed by the passwords request when clicking on the mintupdate shield.
This behaviour can be suppressed by changing the sudoers file in /etc
change the 'robert' below with your own name to make this work.
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# /etc/sudoers
#
# This file MUST be edited with the 'visudo' command as root.
#
# See the man page for details on how to write a sudoers file.
#
Defaults env_reset
# Host alias specification
# User alias specification
# Cmnd alias specification
# User privilege specification
root ALL=(ALL) ALL
# Allow members of group sudo to execute any command after they have
# provided their password
# (Note that later entries override this, so you might need to move
# it further down)
%sudo ALL=(ALL) ALL
#
#includedir /etc/sudoers.d
# Members of the admin group may gain root privileges
%admin ALL=(ALL) ALL
robert ALL = NOPASSWD: /usr/bin/mintupdate
robert ALL = NOPASSWD: /usr/sbin/synaptic
robert ALL = NOPASSWD: /usr/lib/linuxmint/mintUpdate/mintUpdate.py