protected function validateElementValues() {
    		// Iterate over all fields
        	foreach ( self::$mandatoryFields as $field ) {
        		// If the field does not exist then exit with exception
        		if ( array_key_exists($field, $this->attributes) ) {
        			$value = (int) $this->attributes[$field];
        			if ( $value < 0 ) {
        				throw new \SVGCreator\SVGException("The " . $field . " value is lesser than 0, in element " . self::TYPE, 1);
        			}
        		}
        	}
    	}