Method references should be used

Method references are specialized lambda expressions for methods that already have a name. They take the form of objectReference::methodName or ClassName::methodName. When a lambda does nothing but call an existing method, it can be much clearer to use a method reference instead.

Noncompliant Code Example

Set roster = transferElements(rosterSource, 
      () -> { return new HashSet<>(); }  // Noncompliant
);

Compliant Solution

Set roster = transferElements(rosterSource, HashSet::new);