code: def setKeyForAPI(cls, siteStore, apiName, apiKey):
          
          existingKey = cls.getKeyForAPI(siteStore, apiName)
          if existingKey is None:
              return cls(store=siteStore, apiName=apiName, apiKey=apiKey)
          existingKey.apiKey = apiKey
          return existingKey
docs: Set the API key for the named API, overwriting any existing key.
  
          @param siteStore: The site store to install the key in.
          @type siteStore: L{axiom.store.Store}
  
          @param apiName: The name of the API.
          @type apiName: C{unicode} (L{APIKey} constant)
  
          @param apiKey: The key for accessing the API.
          @type apiKey: C{unicode}
  
          @rtype: L{APIKey}