def enumeration_values
      enumeration = @xml.xpath('./xs:restriction/xs:enumeration', {'xs' => 'http://www.w3.org/2001/XMLSchema'})
      if enumeration.length > 0
        return enumeration.map {|elem| [elem.attributes['value'].value, elem.xpath('./xs:annotation/xs:documentation', {'xs' => 'http://www.w3.org/2001/XMLSchema'}).text]}
      else
        raise "Not an enumeration"
      end    
    end
def enumeration_values
      enumeration = @xml.xpath('./xs:restriction/xs:enumeration', {'xs' => 'http://www.w3.org/2001/XMLSchema'})
      if enumeration.length > 0
        return enumeration.map {|elem| [elem.attributes['value'].value, elem.xpath('./xs:annotation/xs:documentation', {'xs' => 'http://www.w3.org/2001/XMLSchema'}).text]}
      else
        raise "Not an enumeration"
      end    
    end
Returns the list of values for this enumeration