@Test void parsesEmptyListOfHosts_toDefault() {
    assertThat(new InitialEndpointSupplier(HTTP, "").get().endpoints())
      .containsExactly(Endpoint.of("localhost", 9200));
  }
This helps ensure old setups don't break (provided they have http port 9200 open)
zipkin-server/src/test/java/zipkin2/server/internal/elasticsearch/InitialEndpointSupplierTest.java