nd4j-common/src/main/java/org/nd4j/util/StringUtils.java
public static String simpleHostname(String fullHostname) {
        if (InetAddresses.isInetAddress(fullHostname)) {
            return fullHostname;
        }
        int offset = fullHostname.indexOf('.');
        if (offset != -1) {
            return fullHostname.substring(0, offset);
        }
        return fullHostname;
    }
public static String simpleHostname(String fullHostname) {
        if (InetAddresses.isInetAddress(fullHostname)) {
            return fullHostname;
        }
        int offset = fullHostname.indexOf('.');
        if (offset != -1) {
            return fullHostname.substring(0, offset);
        }
        return fullHostname;
    }
Given a full hostname, return the word upto the first dot.
@param fullHostname the full hostname
@return the hostname to the first dot