Constant UPDATE_ISSUE_TOKEN 

pub const UPDATE_ISSUE_TOKEN: &str = "mutation($input:UpdateIssueInput!,$nestedFirst:Int!,$boardItems:Int!,$duplicates:Boolean!,$relationshipEvents:[IssueTimelineItemsItemType!]=[BLOCKED_BY_ADDED_EVENT,BLOCKED_BY_REMOVED_EVENT,BLOCKING_ADDED_EVENT,BLOCKING_REMOVED_EVENT,PARENT_ISSUE_ADDED_EVENT,PARENT_ISSUE_REMOVED_EVENT]){updateIssue(input:$input){issue{__typename id number title body url createdAt updatedAt state stateReason(enableDuplicate:$duplicates) repository{nameWithOwner} parent{id} subIssuesSummary{total} commentCount:comments{totalCount} relationshipEvents:timelineItems(itemTypes:$relationshipEvents){totalCount}\n      labels(first:$nestedFirst){nodes{id name color}pageInfo{hasNextPage}}\n      projectItems(first:$boardItems){nodes{id updatedAt project{id number}\n        fieldValues(first:$nestedFirst){nodes{\n          ... on ProjectV2ItemFieldSingleSelectValue{name field{\n            ... on ProjectV2SingleSelectField{id name options{id name}}\n          }}\n          ... on ProjectV2ItemFieldTextValue{text field{... on ProjectV2Field{id name}}}\n        }pageInfo{hasNextPage}}}pageInfo{hasNextPage endCursor}}}}}";

UPDATE_ISSUE, selecting what a read of the issue updated selects — every part of its change token, and no comment — inline, so its root fields are the plain document’s.

What a targeted update sends in the plain document’s place, so the version it answers is the one its own last response spells (GitHubProjectsSource::written_tokens). It costs the one point the plain document does.