anchor.diff:  
     # Deletes an image from an artwork in my collection
     deleteArtworkImage(input: DeleteArtworkImageInput!): DeleteArtworkImagePayload
  +
  +  # Remove a bank account
  +  deleteBankAccount(input: DeleteBankAccountInput!): DeleteBankAccountPayload
   
     # Remove a credit card
     deleteCreditCard(input: DeleteCreditCardInput!): DeleteCreditCardPayload
  
positive.code:   # A list of authenticated external services
    authentications: [AuthenticationType!]!
  
    # Returns a single bidder position
    bidderPosition(id: String!): BidderPositionResult
  
  
negative.code:   last4: String!
  }
  
  # A connection to a list of items.
  type BankAccountConnection {
    # A list of edges.
    edges: [BankAccountEdge]
  
    # Information to aid in pagination.
    pageInfo: PageInfo!
  }
  
  # An edge in a connection.
  type BankAccountEdge {
    # A cursor for use in pagination
    cursor: String!
  
    # The item at the end of the edge
    node: BankAccount
  }
  
  type BankAccountMutationFailure {
    mutationError: GravityMutationError
  }
  
  type BankAccountMutationSuccess {
    bankAccount: BankAccount
    bankAccountEdge: BankAccountEdge
  }
  
  union BankAccountMutationType = BankAccountMutationFailure | BankAccountMutationSuccess
  
  type Bidder implements Node {
    createdAt(
      format: String
  