code: public static RepositoryId extractRepositoryFromScmUrl(String url) {
  		if (StringUtils.isEmpty(url))
  			return null;
  		int ghIndex = url.indexOf(HOST_DEFAULT);
  		if (ghIndex == -1 || ghIndex + 1 >= url.length())
  			return null;
  		if (!url.endsWith(SUFFIX_GIT))
  			return null;
  		url = url.substring(ghIndex + HOST_DEFAULT.length() + 1, url.length()
  				- SUFFIX_GIT.length());
  		return RepositoryId.createFromId(url);
  	}
docs: Extra repository id from given SCM URL
  
  @param url
  @return repository id or null if extraction fails