question: private Node deleteMin ( Node x ) { if ( x . left == null ) return x . right ; x . left = deleteMin ( x . left ) ; x . size = 1 + size ( x . left ) + size ( x . right ) ; x . height = 1 + Math . max ( height ( x . left ) , height ( x . right ) ) ; return balance ( x ) ; }
target:  Removes the smallest key and associated value from the given subtree.