variable missing support for accessing testPart or sectionPart duration

[davemckain]

The last paragraph of the spec for timeLimits says:

The time spent on the test is recorded as if it were a built-in response variable called duration delcared at the test-level and of base-type duration and single cardinality. Similarly, time spent on test parts or sections are treated as built-in response variables declared within each respective scope. The values of these durations can be refered to during outcomeProcessing by using the variable name duration prefixed with the identifier of the part or section followed by the period character. See the variable expression for further information.

This is currently not supported.