The ternary syntax is one place where an empty block won't suffice — there must be an expression in both branches. In such a case, you can use `nothing` (which is also what an empty block will return). That said, it's more typical to refactor these cases into short-circuiting expressions:
cond ? expr : nothing # could be written as: cond && expr cond ? nothing : expr # becomes: cond || expr
