code: def get_defaults(rq, v, metadata):
      
      glogger.debug("Metadata with defaults: {}".format(metadata))
      if 'defaults' not in metadata:
          return None
      defaultsDict = _getDictWithKey(v, metadata['defaults'])
      if defaultsDict:
          return defaultsDict[v]
      return None
docs: Returns the default value for a parameter or None