formula:
https://api.github.com/repos/[user]/[reponame]/issues/[issue_id]/comments
example:
https://api.github.com/repos/docker/compose/issues/1786/comments
then see the string value of body comment
formula:
https://api.github.com/repos/[user]/[reponame]/issues/[issue_id]/comments
example:
https://api.github.com/repos/docker/compose/issues/1786/comments
then see the string value of body comment