anchor.diff:  This call is idempotent w.r.t the `ref` supplied. The JSON `data` is opaque and used only for the client's reference.
   
   + `ref` (string) - The external ID for the recharger
  -+ `data` (object) - An arbitrary JSON data associated with this recharger
  ++ `data` (object) - Arbitrary JSON data associated with this recharger
   
   + Request (application/json)
   
  
positive.code: 
  * *Rechargers* are **Asset** accounts, and thus tend to have an internal negative balance.
  * *Wallets* are **Liability** accounts, where the credit is owed to the users.
  * *Revenues* are **Owner's Equity** accounts, because these are revnues that the owner of the system has earned.
  * Going by the standard equation, **Assets = Liabilities + Owner's Equity**. This equation should always hold true, and is used internally and externally to balance the books.
  * A *Recharge* transaction will move credit from a  Recharger (Asset) to a Wallet (Liability).
  * A *Spend* transaction will move credit from a  Wallet (Liability) to a revenue account (Owner's Equity).
  * A *Refund* transaction will move credit from a  Revenue account (Owner's Equity) to a Wallet (Liability).
  ## Group Account Management
  
  These calls relate to account management, including creating accounts and checking balances.
  
  ## Wallet [/wallets/{id}]
  
  Wallets are user accounts that hold their credit.
  
  
negative.code: This call is idempotent w.r.t the `ref` supplied. The JSON `data` is opaque and used only for the client's reference.
  
  + `ref` (string) - The external ID of the user wallet
  + `data` (object) - Arbitrary JSON data associated with this wallet
  
  + Request (application/json)
  
          {
              "ref": "ABCD1234",
              "data": {
                  "k1": "v1"
              }
          }
  
  
  + Response 200 (application/json)
  
          {
              "ref": "ABCD1234",
              "data": {
                  "k1": "v1"
              },
              "balance": 0.0
          }
  
  ## Rechargers [/rechargers]
  
  Rechargers are accounts that supply credit to user wallets.
  
  