code: public static RuntimeEnvironmentBuilder getDefaultInMemory() {
          RuntimeEnvironmentBuilder builder = new RuntimeEnvironmentBuilder(new DefaultRuntimeEnvironment(null, false));
          builder
          .addConfiguration("drools.processSignalManagerFactory", DefaultSignalManagerFactory.class.getName())
          .addConfiguration("drools.processInstanceManagerFactory", DefaultProcessInstanceManagerFactory.class.getName());
  
          return builder;
      }
docs: Provides default configuration of <code>RuntimeEnvironmentBuilder</code> that is based on:
  <ul>
  <li>DefaultRuntimeEnvironment</li>
  </ul>
  but it does not have persistence for process engine configured so it will only store process instances in memory
  @return new instance of <code>RuntimeEnvironmentBuilder</code> that is already preconfigured with defaults
  
  @see DefaultRuntimeEnvironment