"User is in Multi-User Field" Condition on Workflow Transition

There are two new Workflow Transition Conditions that we'd like:

• User Is In Field
• User Is In Multi-User Field

The two are quite similar, what we really want is the latter.

The condition here is that the user who attempts to execute that transition should be referenced in a named field on the issue.

So assume a support workflow with an approval step. The support person says "in order to give privileges to System X, one of managers A, B, or C must approve the request." The support person puts A, B, and C into the "Approvers" field, and only A, B, or C can approve the request to go forward.

This is logically EXTREMELY similar to "User Is In Group Custom Field", except that it relies on individual users rather than JIRA groups.