code: public void setFreeBusyType(FreeBusyType freeBusyType) {
  		replace(FBTYPE, (freeBusyType == null) ? null : freeBusyType.getValue());
  	}
docs: <p>
  Sets the FBTYPE (free busy type) parameter value.
  </p>
  <p>
  This parameter is used by the {@link FreeBusy} property. It defines
  whether the person is "free" or "busy" over the time periods that are
  specified in the property value. If this parameter is not set, the user
  should be considered "busy" during these times.
  </p>
  @param freeBusyType the free busy type or null to remove
  @see <a href="http://tools.ietf.org/html/rfc5545#page-20">RFC 5545
  p.20</a>