public static <T> T checkExist(T reference, String message, Object... args) {
		if (reference == null) {
			throw new IllegalArgumentException(String.format(message, args));
		}
		return reference;
	}
Ensures that an object reference passed as a parameter to the calling method is not null.

@param <T>       type
@param reference reference
@param message   error message template
@param args      error formatting element
@return the non-null reference that was validated
ngrinder-core/src/main/java/org/ngrinder/common/util/Preconditions.java