code: public void free() {
          if (handle != 0L) {
              Log.d(LogDomain.REPLICATOR, "handle: " + handle);
              Log.d(
                  LogDomain.REPLICATOR,
                  "replicatorContext: " + replicatorContext + " $" + replicatorContext.getClass());
              Log.d(
                  LogDomain.REPLICATOR,
                  "socketFactoryContext: " + socketFactoryContext + " $" + socketFactoryContext.getClass());
              free(handle, replicatorContext, socketFactoryContext);
              handle = 0L;
          }
  
          if (replicatorContext != null) {
              CONTEXT_TO_C4_REPLICATOR_MAP.remove(this.replicatorContext);
              replicatorContext = null;
          }
      }
docs: It was introduced during the massive refactor to clean up the code, 3/13/2019