anchor.diff:    signatures: Bytes!
   }
   
  -type Account @entity {
  -  id: ID!                          # address
  -  safes: [SafeOwner]!              @derivedFrom(field: "owner")
  -  sentTokens: [TokenTransfer]!     @derivedFrom(field: "from")
  -  receivedTokens: [TokenTransfer]! @derivedFrom(field: "to")
  -  depots: [Depot]!                 @derivedFrom(field: "supplier")
  -  bridgedTokens: [BridgeEvent]!    @derivedFrom(field: "supplier")
  -}
  -
   # A mapping table is the more performant way to represent many-to-many
   # relationships
   type SafeOwner @entity {
     id: ID!               # Set to safe.id-owner.id
     owner: Account!
     safe: Safe!
  -}
  -
  -type PrepaidCardTransfer @entity {
  -  id: ID!              # safe.id-from-to-txnhash
  -  from: Account!
  -  to: Account!
   }
   
   type TokenTransfer @entity {
  
positive.code: type Safe @entity {
    id: ID!                          # safe address
    createdAt: BigInt!               # unix time
    owners: [SafeOwner]!             @derivedFrom(field: "safe")
    sentTokens: [TokenTransfer]!     @derivedFrom(field: "fromSafe")
    receivedTokens: [TokenTransfer]! @derivedFrom(field: "toSafe")
    safeTxns: [SafeTransaction]!     @derivedFrom(field: "safe")
    depot: Depot                     @derivedFrom(field: "safe")
    merchant: MerchantSafe           @derivedFrom(field: "safe")
    prepaidCard: PrepaidCard         @derivedFrom(field: "safe")
  }
  
  type Depot @entity {
  
negative.code:   infoDid: String
    createdPrepaidCards: [PrepaidCard]! @derivedFrom(field: "createdFromDepot")
    bridgedTokens: [BridgeEvent]!       @derivedFrom(field: "depot")
  }
  
  type PrepaidCard @entity {
  