$ ./twig_replace_test.pl 
TWEAK: <tweak name="T1"><description>D1</description></tweak> (Found 0 other parsed tweaks with the same name)
TWEAK: <tweak name="T2"><description>D2</description></tweak> (Found 0 other parsed tweaks with the same name)
TWEAK: <tweak name="T3"><description>D3</description></tweak> (Found 0 other parsed tweaks with the same name)
TWEAK: <tweak name="T2"><description>This should overwrite the old T2.</description></tweak> (Found 1 other parsed tweaks with the same name)
	Replacing
		<tweak name="T2"><description>D2</description></tweak>
	with
		<tweak name="T2"><description>This should overwrite the old T2.</description></tweak>
TWIG: