Layer

this graphQL type doesn't have a 1-to-1 correspondence to a row in the database we omit using a required ID field because our IDs are the materialIDs, which which although are going to be unique per elevation, usage of these IDs for the entire system will not be unique. This can lead to problems for the graphQL client caching implementations that normalizes data based on the ID fields. graphQL client impls such as Apollo can still correctly cache instances of graphQL types that do not have ID fields. see here: https://www.apollographql.com/docs/react/advanced/caching.html#normalization