Constant DRAFT 

pub const DRAFT: &str = "query($id:ID!,$nestedFirst:Int!,$boardItems:Int!){\n      node(id:$id){__typename ... on DraftIssue{id title body createdAt updatedAt\n        projectV2Items(first:$boardItems){nodes{id project{id number}\n        fieldValues(first:$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}}}}\n    }";

One board draft by its own node id, with the board item it sits in.

A draft is not an issue, so ISSUE reaches it and reads nothing of it; this is the second read that answers it. DraftIssue.projectV2Items names the board item a draft is — GitHub links a draft to one item — with the same [board_item_values!] the issue fragment reads, so a draft reached by id resolves through the same resolver a board listing hands it to, and nothing has to list the board to find one.