public String getEmulatorEndpoint() {
        return getHost() + ":" + getMappedPort(HTTP_PORT);
    }
@return a <code>host:port</code> pair corresponding to the address on which the emulator is
reachable from the test host machine. Directly usable as a parameter to the
com.google.cloud.ServiceOptions.Builder#setHost(java.lang.String) method.
modules/gcloud/src/main/java/org/testcontainers/containers/DatastoreEmulatorContainer.java