code: protected Object[] getSourceValues() {
  		Object[] values = new Object[sourceValueModels.length];
  		for (int i = 0; i < values.length; i++) {
  			values[i] = sourceValueModels[i].getValue();
  		}
  		return values;
  	}
docs: Convenience method to extract values from all sourceValueModels that
  influence the derived value.
  
  @return an <code>Array</code> containing the source values in the same
  order as the source valueModels were defined.