assert_equal("...\357\254\203ciency could not be...".force_encoding('UTF-8'),excerpt("That's why e\357\254\203ciency could not be helped".force_encoding('UTF-8'),'could',8))
# .mb_chars always returns UTF-8, even in 1.9. This is not great, but it's how it works. Let's work this out.
# assert_equal("...\203ciency could not be...", excerpt("That's why e\357\254\203ciency could not be helped".force_encoding("BINARY"), 'could', 8))