anchor.diff:  pluginProperty=San%3DFrancisco&pluginProperty=billing_address%3Daddress%5Bpostcode%5D%3D94114
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  -The mechanism also works for receiving information back from the plugin; the plugin can return a piece of json that will be embedded in the json response; for instance, the plugin could return a spefic key:
  +The mechanism also works for receiving information back from the plugin; the plugin can return a piece of json that will be embedded in the json response; for instance, the plugin could return a specific key:
   
   [source,bash]
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positive.code: === Plugin Properties
  
  In the sections below, we are presenting APIs to manage payment methods and payments operations. Those APIs have been built to be as generic as possible and because each plugin/gateway has its own specificities, they also need to take that into account:
  
  * For each API, one can specify custom properties by using query parameters -- those query parameteres should be URL encoded
  * Kill Bill will deserialize the query parameters and pass them straight to the plugin
  
  This mechanism allows to pass information from the client of the API to the plugin, and all that is opaque to Kill Bill; for instance, in order to specify the following two plugin properties:
  
  [source,bash]
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negative.code:            "key": "pluginSpecificKey",
             "value": "9876543210"
           }]
  ----