void add(final double value) {
		if (Double.isNaN(value)) {
			throw new IllegalArgumentException();
		}

		_values[nextIndex()] = value;
	}
Insert the given value at the next free <i>slot</i> (position).

@param value the value to insert
@throws IndexOutOfBoundsException if all sample values has been set
@throws IllegalArgumentException if the given value is not a number,
        {@code Double.isNaN(value)} returns {@code true}
jenetics.tool/src/main/java/io/jenetics/tool/trial/Sample.java