code: function cachedTypeDetector(type) {
  	if (!cache.has(type)) {
  		cache.set(type, (input) => isType(type, input) || typeInAncestry(type, input));
  	}
  
  	return cache.get(type);
  }
docs: Ensure a delegate function exists for the given type and return it
  
  @param   {string}    type
  @return  {function}  detector