what is restcall,pathcall,namedcall in lagom.javadsl.api.Descriptor;
<p>I am new to microservices and Lagom framework, in the service api where we make ServiceCalls I do not understand the difference of <em><code>namedcall</code></em>, <em><code>pathcall</code></em> and <em><code>restcall</code></em>. where and when should we use which? </p>

<p>for instance in these calls:</p>

<pre><code>  ServiceCall&lt;NotUsed, Cargo, Done&gt; register();
  restCall(Method.POST, "/api/registration", register()

  ServiceCall&lt;NotUsed, NotUsed, Source&lt;Cargo, ?&gt;&gt; getLiveRegistrations();
  pathCall("/api/registration/live", getLiveRegistrations())

  ServiceCall&lt;User, NotUsed&gt; createUser();
  namedCall("/api/users", this::createUser)
</code></pre>