private void addSystemEnvironment(ConfigurableEnvironment environment, String... pairs) {
		MutablePropertySources sources = environment.getPropertySources();
		Map<String, Object> map = getOrAdd(sources, "testsysenv");
		for (String pair : pairs) {
			int index = getSeparatorIndex(pair);
			String key = pair.substring(0, index > 0 ? index : pair.length());
			String value = index > 0 ? pair.substring(index + 1) : "";
			map.put(key.trim(), value.trim());
		}
	}
@author Spencer Gibb
@author Matt Jenkins
@author Olga Maciaszek-Sharma
@author Tim Ysewyn
spring-cloud-netflix-eureka-client/src/test/java/org/springframework/cloud/netflix/eureka/EurekaClientAutoConfigurationTests.java