&& is_array( $_POST[ 'widget-' . $this->id_base ] ) ) {
				$settings = $_POST[ 'widget-' . $this->id_base ];
			} elseif ( isset( $_POST['id_base'] ) && $_POST['id_base'] == $this->id_base ) {
				$num      = $_POST['multi_number'] ? (int) $_POST['multi_number'] : (int) $_POST['widget_number'];
				$settings = array( $num => array() );
			} else {
				return;
			}

			foreach ( $settings as $number => $new_instance ) {
				$new_instance = stripslashes_deep( $new_instance );
				$this->_set( $number );

				$old_instance = isset( $all_instances[ $number ] ) ? $all_instances[ $number ] : array();

				$was_cache_addition_suspended = wp_suspend_cache_addition();
				if ( $this->is_preview() && ! $was_cache_addition_suspended ) {
					wp_suspend_cache_addition( true );
				}

				$instance = $this->update( $new_instance, $old_instance );

				if ( $this->is_preview() ) {
					wp_suspend_cache_addition( $was_cache_addition_suspended );
				}

				/**
				 * Filters a widget's settings before saving.
				 *
				 * Returning false will effectively short-circuit the widget's ability
				 * to update settings.
				 *
				 * @since 2.8.0
				 *
				 * @param array     $instance     The current widget instance's settings.
				 * @param array     $new_instance Array of new widget settings.
				 * @param array     $old_instance Array of old widget settings.
				 * @param WP_Widget $widget       The current widget instance.
				 */
				$instance = apply_filters( 'widget_update_callback', $instance, $new_instance, $old_instance, $this );

				if ( false !== $instance ) {
					$all_instances[ $number ] = $instance;
				}

				break; // Run only once.
			}
		}

		$this->save_settings( $all_instances );
		$this->updated = true;
	}

	/**
	 * Generates the widget control form (Do NOT override).
	 *
	 * @since 2.8.0
	 *
	 * @param int|array $widget_args {
	 *     Optional. Internal order number of the widget instance, or array of multi-widget arguments.
	 *     Default 1.
	 *
	 *     @type int $number Number increment used for multiples of the same widget.
	 * }
	 * @return string|null
	 */
	public function form_callback( $widget_args = 1 ) {
		if ( is_numeric( $widget_args ) ) {
			$widget_args = array( 'number' => $widget_args );
		}

		$widget_args   = wp_parse_args( $widget_args, array( 'number' => -1 ) );
		$all_instances = $this->get_settings();

		if ( -1 == $widget_args['number'] ) {
			// We echo out a form where 'number' can be set later.
			$this->_set( '__i__' );
			$instance = array();
		} else {
			$this->_set( $widget_args['number'] );
			$instance = $all_instances[ $widget_args['number'] ];
		}

		/**
		 * Filters the widget instance's settings before displaying the control form.
		 *
		 * Returning false effectively short-circuits display of the control form.
		 *
		 * @since 2.8.0
		 *
		 * @param array     $instance The current widget instance's settings.
		 * @param WP_Widget $widget   The current widget instance.
		 */
		$instance = apply_filters( 'widget_form_callback', $instance, $this );

		$return = null;

		if ( false !== $instance ) {
			$return = $this->form( $instance );

			/**
			 * Fires at the end of the widget control form.
			 *
			 * Use this hook to add extra fields to the widget form. The hook
			 * is only fired if the value passed to the 'widget_form_callback'
			 * hook is not false.
			 *
			 * Note: If the widget has no form, the text echoed from the default
			 * form method can be hidden using CSS.
			 *
			 * @since 2.8.0
			 *
			 * @param WP_Widget $widget   The widget instance (passed by reference).
			 * @param null      $return   Return null if new fields are added.
			 * @param array     $instance An array of the widget's settings.
			 */
			do_action_ref_array( 'in_widget_form', array( &$this, &$return, $instance ) );
		}

		return $return;
	}

	/**
	 * Registers an instance of the widget class.
	 *
	 * @since 2.8.0
	 *
	 * @param int $number Optional. The unique order number of this widget instance
	 *                    compared to other instances of the same class. Default -1.
	 */
	public function _register_one( $number = -1 ) {
		wp_register_sidebar_widget(
			$this->id,
			$this->name,
			$this->_get_display_callback(),
			$this->widget_options,
			array( 'number' => $number )
		);

		_register_widget_update_callback(
			$this->id_base,
			$this->_get_update_callback(),
			$this->control_options,
			array( 'number' => -1 )
		);

		_register_widget_form_callback(
			$this->id,
			$this->name,
			$this->_get_form_callback(),
			$this->control_options,
			array( 'number' => $number )
		);
	}

	/**
	 * Saves the settings for all instances of the widget class.
	 *
	 * @since 2.8.0
	 *
	 * @param array $settings Multi-dimensional array of widget instance settings.
	 */
	public function save_settings( $settings ) {
		$settings['_multiwidget'] = 1;
		update_option( $this->option_name, $settings );
	}

	/**
	 * Retrieves the settings for all instances of the widget class.
	 *
	 * @since 2.8.0
	 *
	 * @return array Multi-dimensional array of widget instance settings.
	 */
	public function get_settings() {

		$settings = get_option( $this->option_name );

		if ( false === $settings ) {
			$settings = array();
			if ( isset( $this->alt_option_name ) ) {
				// Get settings from alternative (legacy) option.
				$settings = get_option( $this->alt_option_name, array() );

				// Delete the alternative (legacy) option as the new option will be created using `$this->option_name`.
				delete_option( $this->alt_option_name );
			}
			// Save an option so it can be autoloaded next time.
			$this->save_settings( $settings );
		}

		if ( ! is_array( $settings ) && ! ( $settings instanceof ArrayObject || $settings instanceof ArrayIterator ) ) {
			$settings = array();
		}

		if ( ! empty( $settings ) && ! isset( $settings['_multiwidget'] ) ) {
			// Old format, convert if single widget.
			$settings = wp_convert_widget_settings( $this->id_base, $this->option_name, $settings );
		}

		unset( $settings['_multiwidget'], $settings['__i__'] );

		return $settings;
	}
}
 $name ) {
		if ( ! in_array( $name, $this->deprecated_properties, true ) ) {
			return;
		}

		$new_name = $name . '_handles';

		if ( ! property_exists( $this, $new_name ) || ! is_array( $this->{$new_name} ) ) {
			return null;
		}

		if ( count( $this->{$new_name} ) > 1 ) {
			return $this->{$new_name};
		}
		return isset( $this->{$new_name}[0] ) ? $this->{$new_name}[0] : null;
	}

	/**
	 * Proxies checking for deprecated properties for script and style handles for backward compatibility.
	 * Checks whether the corresponding new property has the first item in the array provided.
	 *
	 * @since 6.1.0
	 *
	 * @param string $name Deprecated property name.
	 *
	 * @return boolean Returns true when for the new property the first item in the array exists,
	 *                     or false otherwise.
	 */
	public function __isset( $name ) {
		if ( ! in_array( $name, $this->deprecated_properties, true ) ) {
			return false;
		}

		$new_name = $name . '_handles';
		return isset( $this->{$new_name}[0] );
	}

	/**
	 * Proxies setting values for deprecated properties for script and style handles for backward compatibility.
	 * Sets the value for the corresponding new property as the first item in the array.
	 * It also allows setting custom properties for backward compatibility.
	 *
	 * @since 6.1.0
	 *
	 * @param string $name  Property name.
	 * @param mixed  $value Property value.
	 */
	public function __set( $name, $value ) {
		if ( ! in_array( $name, $this->deprecated_properties, true ) ) {
			$this->{$name} = $value;
			return;
		}

		$new_name = $name . '_handles';

		if ( is_array( $value ) ) {
			$filtered = array_filter( $value, 'is_string' );

			if ( count( $filtered ) !== count( $value ) ) {
					_doing_it_wrong(
						__METHOD__,
						sprintf(
							/* translators: %s: The '$value' argument. */
							__( 'The %s argument must be a string or a string array.' ),
							'<code>$value</code>'
						),
						'6.1.0'
					);
			}

			$this->{$new_name} = array_values( $filtered );
			return;
		}

		if ( ! is_string( $value ) ) {
			return;
		}

		$this->{$new_name} = array( $value );
	}

	/**
	 * Renders the block type output for given attributes.
	 *
	 * @since 5.0.0
	 *
	 * @param array  $attributes Optional. Block attributes. Default empty array.
	 * @param string $content    Optional. Block content. Default empty string.
	 * @return string Rendered block type output.
	 */
	public function render( $attributes = array(), $content = '' ) {
		if ( ! $this->is_dynamic() ) {
			return '';
		}

		$attributes = $this->prepare_attributes_for_render( $attributes );

		return (string) call_user_func( $this->render_callback, $attributes, $content );
	}

	/**
	 * Returns true if the block type is dynamic, or false otherwise. A dynamic
	 * block is one which defers its rendering to occur on-demand at runtime.
	 *
	 * @since 5.0.0
	 *
	 * @return bool Whether block type is dynamic.
	 */
	public function is_dynamic() {
		return is_callable( $this->render_callback );
	}

	/**
	 * Validates attributes against the current block schema, populating
	 * defaulted and missing values.
	 *
	 * @since 5.0.0
	 *
	 * @param array $attributes Original block attributes.
	 * @return array Prepared block attributes.
	 */
	public function prepare_attributes_for_render( $attributes ) {
		// If there are no attribute definitions for the block type, skip
		// processing and return verbatim.
		if ( ! isset( $this->attributes ) ) {
			return $attributes;
		}

		foreach ( $attributes as $attribute_name => $value ) {
			// If the attribute is not defined by the block type, it cannot be
			// validated.
			if ( ! isset( $this->attributes[ $attribute_name ] ) ) {
				continue;
			}

			$schema = $this->attributes[ $attribute_name ];

			// Validate value by JSON schema. An invalid value should revert to
			// its default, if one exists. This occurs by virtue of the missing
			// attributes loop immediately following. If there is not a default
			// assigned, the attribute value should remain unset.
			$is_valid = rest_validate_value_from_schema( $value, $schema, $attribute_name );
			if ( is_wp_error( $is_valid ) ) {
				unset( $attributes[ $attribute_name ] );
			}
		}

		// Populate values of any missing attributes for which the block type
		// defines a default.
		$missing_schema_attributes = array_diff_key( $this->attributes, $attributes );
		foreach ( $missing_schema_attributes as $attribute_name => $schema ) {
			if ( isset( $schema['default'] ) ) {
				$attributes[ $attribute_name ] = $schema['default'];
			}
		}

		return $attributes;
	}

	/**
	 * Sets block type properties.
	 *
	 * @since 5.0.0
	 *
	 * @param array|string $args Array or string of arguments for registering a block type.
	 *                           See WP_Block_Type::__construct() for information on accepted arguments.
	 */
	public function set_props( $args ) {
		$args = wp_parse_args(
			$args,
			array(
				'render_callback' => null,
			)
		);

		$args['name'] = $this->name;

		// Setup attributes if needed.
		if ( ! isset( $args['attributes'] ) || ! is_array( $args['attributes'] ) ) {
			$args['attributes'] = array();
		}

		// Register core attributes.
		foreach ( static::GLOBAL_ATTRIBUTES as $attr_key => $attr_schema ) {
			if ( ! array_key_exists( $attr_key, $args['attributes'] ) ) {
				$args['attributes'][ $attr_key ] = $attr_schema;
			}
		}

		/**
		 * Filters the arguments for registering a block type.
		 *
		 * @since 5.5.0
		 *
		 * @param array  $args       Array of arguments for registering a block type.
		 * @param string $block_type Block type name including namespace.
		 */
		$args = apply_filters( 'register_block_type_args', $args, $this->name );

		foreach ( $args as $property_name => $property_value ) {
			$this->$property_name = $property_value;
		}
	}

	/**
	 * Get all available block attributes including possible layout attribute from Columns block.
	 *
	 * @since 5.0.0
	 *
	 * @return array Array of attributes.
	 */
	public function get_attributes() {
		return is_array( $this->attributes ) ?
			$this->attributes :
			array();
	}
}