title: How to map a list of string to emptylists?
body: <p>I have a set of String and want to map each of them to an empty list then return. I know a for loop could solve it, but is there a good way to do it with Java Stream?</p>
  
  <p>e.g: I have a Set of <code>{"a", "b", "c"}</code></p>
  
  <p>and I want to return a map <code>Map&lt;String, List&lt;Object&gt;&gt;</code> to be something like <code>{"a": emptyList(), "b": emptyList(), "c": emptyList()}</code></p>