Casting a Spel expression

Happy Halloween!

I have a SAML IDP providing roles, and shinyproxy is populating the SHINYPROXY_USERGROUPS environment variable like this
SHINYPROXY_USERGROUPS: CN=DATA TEAM,OU=DISTRIBUTION LISTS,…

I am trying to add group contingencies. I have tried access-groups and access-expressions.

of the forms:

access-groups: [DATA TEAM]

–or–

access-expression: “#{proxy.getRuntimeValue(‘SHINYPROXY_USERGROUPS’).contains(‘DATA TEAM’) }”

I have tried a couple variations on the access-expression.

Is there any way to log these values to see what the data structures are? I received an error that the result of proxy.getRuntimeValue didn’t have a contains method, so I take it that it isn’t a string, possible some list, but I don’t know how to index it.