How to completely remove an issue from GitHub?

Question

Is it possible to completely remove an issue from the GitHub issue tracker?

Answer 1

Update Nov 2018: You now can delete your issues!
See "Github - remove issues entered in error"

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At May 2018, original answer:

Three 8 years later, and closing issues remains the answer (still no deletion possible).
See "The Ghost of Issues Past", where GitHub advise to check and close:

• issues opened over a year ago state:open created:<2013-01-01
• the ones I'm involved with involves:twp state:open created:<2013-01-01
• and those not updated in the last year involves:twp state:open updated:<2013-01-01