how do I set multi-value property with only one value using SlingPostServlet?

[sam lee]

I tried:

curl -u admin:admin -F'foo=bar' -F'foo=' http://localhost:8888/some/path

but this creates property foo to be {bar,}  (second element is empty).

I also tried

curl -u admin:admin -F'foo=bar' -F'foo=null' http://localhost:8888/some/path

but still it failed to create a multi-value property where only one value is
initialized.