How to close the connection.

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Jest did not exit one second after the test run has completed.

This usually means that there are asynchronous operations that weren't stopped in your tests. Consider running Jest with --detectOpenHandles to troubleshoot this issue.

When I write unit tests with jest the test does not end. I would love to close the connection like in the following example, is that possible?

const grid = require('gridfs-stream');
gfs = grid(db, mongo);
gfs.close()