title: Sense of symbols in TypeScript
body: <p>What is the sense of symbols in TypeScript? Coming from Java it seems a bit redundant to use together with an interface declaration. Why do I have to set symbols in TypeScript? i.e. following code segment:</p>
  
  <pre><code>export const RawProcessOptions = Symbol("RawProcessOptions");
  export interface RawProcessOptions extends ProcessOptions {
  }
  </code></pre>