1) Operation tests
[2020/05/27 18:32:21.120]        should correctly execute aggregation command:
[2020/05/27 18:32:21.120]      Uncaught TypeError: Cannot read property 'a' of null
[2020/05/27 18:32:21.120]       at /data/mci/e0d851a394d8f810a8f1dd830dce044c/src/test/functional/core/operations.test.js:326:30
[2020/05/27 18:32:21.120]       at self._initializeCursor (lib/core/cursor.js:740:9)
[2020/05/27 18:32:21.120]       at handleCallback (lib/core/cursor.js:31:5)
[2020/05/27 18:32:21.120]       at _setCursorNotifiedImpl (lib/core/cursor.js:684:38)
[2020/05/27 18:32:21.120]       at self._endSession (lib/core/cursor.js:693:39)
[2020/05/27 18:32:21.120]       at CoreCursor._endSession (lib/core/cursor.js:394:7)
[2020/05/27 18:32:21.120]       at _setCursorNotifiedImpl (lib/core/cursor.js:693:10)
[2020/05/27 18:32:21.120]       at setCursorNotified (lib/core/cursor.js:684:3)
[2020/05/27 18:32:21.120]       at done (lib/core/cursor.js:450:16)
[2020/05/27 18:32:21.120]       at queryCallback (lib/core/cursor.js:499:18)
[2020/05/27 18:32:21.120]       at /data/mci/e0d851a394d8f810a8f1dd830dce044c/src/lib/core/connection/pool.js:404:18
[2020/05/27 18:32:21.120]       at _combinedTickCallback (internal/process/next_tick.js:132:7)
[2020/05/27 18:32:21.120]       at process._tickCallback (internal/process/next_tick.js:181:9)