InfixExpression groupRoot= findGroupRoot((InfixExpression) node);
InfixExpression groupRoot= findGroupRoot(node);
	public static IExpressionFragment createFragmentForFullSubtree(InfixExpression node) {		Assert.isNotNull(node);				if(!isAssociativeInfix(node))			return null;				InfixExpression groupRoot= findGroupRoot((InfixExpression) node);		Assert.isTrue(isAGroupRoot(groupRoot));				List groupMembers= GroupMemberFinder.findGroupMembersInOrderFor(node);				return new AssociativeInfixExpressionFragment(groupRoot, groupMembers);	}