in packages/graph-explorer/src/connector/gremlin/mappers/extractRawId.ts [3:13]
function isJanusID(id: any): id is JanusID {
return (
typeof id === "object" &&
"@type" in id &&
typeof id["@type"] === "string" &&
"@value" in id &&
typeof id["@value"] === "object" &&
"relationId" in id["@value"] &&
typeof id["@value"]["relationId"] === "string"
);
}