def resolve
      @leaf ||= begin
        ref = self
        loop do
          break ref unless ref.target.kind_of? MultiGit::Ref
          ref = ref.target
        end
      end
    end
def resolve
      @leaf ||= begin
        ref = self
        loop do
          break ref unless ref.target.kind_of? MultiGit::Ref
          ref = ref.target
        end
      end
    end
Resolves symbolic references and returns the final reference.

 @return [MultGit::Ref]