code: def get_familiarity(self, cache=True):
          
          if not (cache and ('familiarity' in self.cache)):
              response = self.get_attribute('familiarity')
              self.cache['familiarity'] = response['artist']['familiarity']
          return self.cache['familiarity']
docs: Get our numerical estimation of how familiar an artist currently is to the world
          
          Args:
          
          Kwargs:
              cache (bool): A boolean indicating whether or not the cached value should be used (if available). Defaults to True.
          
          Returns:
              A float representing familiarity.
          
          Example:
  
          >>> a = artist.Artist('frank sinatra')
          >>> a.get_familiarity()
          0.65142555825947457
          >>> a.familiarity
          0.65142555825947457
          >>>