code: @SuppressWarnings("unlikely-arg-type")
  	protected final void setPrimitiveValidity(BusPrimitiveInvalidity invalidityReason) {
  		if ((invalidityReason == null && this.invalidityReason != null)
  				|| (invalidityReason != null
  				&& !invalidityReason.equals(BusPrimitiveInvalidityType.VALIDITY_NOT_CHECKED)
  				&& !invalidityReason.equals(this.invalidityReason))) {
  			final BusPrimitiveInvalidity old = this.invalidityReason;
  			this.invalidityReason = invalidityReason;
  			fireValidityChanged(old, this.invalidityReason);
  		}
  	}
docs: Set if this component has invalid
  or not.
  
  <p>This function is supposed to be invoked at least
  from {@link #checkPrimitiveValidity()}.
  
  @param invalidityReason is the reason of the invalidity;
  if <code>null</code> the primitive is valid.