src/main/java/org/jinstagram/utils/Preconditions.java
public static void checkEmptyString(String string, String errorMsg) {
		check(StringUtils.isNotBlank(string), errorMsg);
	}
public static void checkEmptyString(String string, String errorMsg) {
		check(StringUtils.isNotBlank(string), errorMsg);
	}
Checks that a string is not null or empty
@param string   any string
@param errorMsg error message
@throws IllegalArgumentException if the string is null or empty