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GET /repos/{owner}/{repo}/issues/{issue_number}/parentUAT IAT - Get parent issueDELETE /repos/{owner}/{repo}/issues/{issue_number}/sub_issueUAT IAT - Remove sub-issueGET /repos/{owner}/{repo}/issues/{issue_number}/sub_issuesUAT IAT - List sub-issuesPOST /repos/{owner}/{repo}/issues/{issue_number}/sub_issuesUAT IAT - Add sub-issuePATCH /repos/{owner}/{repo}/issues/{issue_number}/sub_issues/priorityUAT IAT - Reprioritize sub-issue