ers:</B><DD><CODE>isPositive</CODE> - Set to <code>false</code> to create a negative duration. When the length
   of the duration is zero, this parameter will be ignored.<DD><CODE>year</CODE> - Year of <code>Duration</code>.<DD><CODE>month</CODE> - Month of <code>Duration</code>.<DT><B>Returns:</B><DD>New <code>Duration</code> created using the specified <code>year</code> and <code>month</code>.<DT><B>Throws:</B><DD><CODE>java.lang.IllegalArgumentException</CODE> - If any values would create an invalid <cod