The "executionStats" section of the explain output in SBE is drastically different from the classic engine. To help in transitioning from the old to the new format, we need a tool which would allow to convert the "executionStats" section from SBE into classic format.

The tool would work off the "queryPlanner" section using it as a backbone for the translated "executionStats" section. For each QSN from the "queryPlanner" section we'd need to map it to an SBE sub-tree in the "executionStats" section based on the nodeId, then collect cumulative execution stats for this sub-tree and attach it to a "stage" element in the "executionStats" tree created from the corresponding QSN.