public function google_maps_zoom() {
			if ( preg_match( '/^([0-9]|[0-1][0-9]|2[0-1])$/', $this->value ) ) {
				$this->result->valid = true;
			} else {
				$this->result->valid = false;
				$this->result->error = sprintf( esc_html__( '%s must be a number between 0 and 21.', 'tribe-common' ), $this->label );
			}
		}