def fallback!
        fallback = Exchange.configuration.api.fallback
        new_api  = fallback.index(api) ? fallback[fallback.index(api) + 1] : fallback.first
        
        if new_api
          @api = new_api
          return true
        end
        
        return false
      end
def fallback!
        fallback = Exchange.configuration.api.fallback
        new_api  = fallback.index(api) ? fallback[fallback.index(api) + 1] : fallback.first
        
        if new_api
          @api = new_api
          return true
        end
        
        return false
      end
Fallback to the next api defined in the api fallbacks. Changes the api for the given instance
 @return [Boolean] true if the fallback was successful, false if not
 @since 1.0
 @version 1.0