package sim;/** * Defines a set of methods a distribution (of values) must provide. */public interface Distribution {	/**	 * Returns the next value.	 * @return the next value.	 */	public double getValue();	/**	 * Returns the distribution's expected value.	 * @return the distribution's expected value.	 */	public double getExpectedValue();	/**	 * Returns the distribution's variance.	 * @return the distribution's variance.	 */    public double getVariance();}