Define a function named unite$\_$lists.

Using a for statement, iterate through the two lists, while finding the common elements in both lists without duplicates.

Snippet $6\mathrm{.}109$ shows an example output:

$>>>$ unite$\_$lists$([2,4,6,8],[3,6,9,12])$

$[2,4,6,8,3,9,12]$

Snippet $6\mathrm{.}109$