anchor.diff:  union BankAccountMutationType =
       BankAccountMutationFailure
     | BankAccountMutationSuccess
  +
  +enum BankAccountTypes {
  +  SEPA_DEBIT
  +  US_BANK_ACCOUNT
  +}
   
   type Bidder implements Node {
     createdAt(
  
positive.code:     before: String
      first: Int
      last: Int
    ): BankAccountConnection
  
    # Returns a single bidder position
  
negative.code: 
    # Last four characters of the account identifier
    last4: String!
  
    # Bank account type
    type: BankAccountTypes!
  }
  
  # A connection to a list of items.
  