use assertArraySubset instead of helper function
use assertArraySubset instead of helper function

pfefferle/wordpress-semantic-linkbacks,dshanske/wordpress-semantic-linkbacks,pfefferle/wordpress-semantic-linkbacks,dshanske/wordpress-semantic-linkbacks,pfefferle/wordpress-semantic-linkbacks,dshanske/wordpress-semantic-linkbacks,dshanske/wordpress-semantic-linkbacks,pfefferle/wordpress-semantic-linkbacks