src/org/kocakosm/pitaya/util/Parameters.java
public static <T> T checkNotNull(T ref, String msg, Object... args)
	{
		if (ref == null) {
			throw new NullPointerException(format(msg, args));
		}
		return ref;
	}
public static <T> T checkNotNull(T ref, String msg, Object... args)
	{
		if (ref == null) {
			throw new NullPointerException(format(msg, args));
		}
		return ref;
	}
Checks that the given reference is not {@code null} and returns it
in case of success.

@param <T> the type of the given reference.
@param ref the reference to test.
@param msg the error message format string.
@param args the error message arguments.

@return the validated (non-{@code null}) reference.

@throws NullPointerException if the given reference is {@code null}.