Astra_Ext_Advanced_Headers_Meta::init_metabox()

		public function init_metabox() {
			add_action( 'add_meta_boxes', array( $this, 'setup_meta_box' ) );
			add_action( 'save_post', array( $this, 'save_meta_box' ) );

			$default_above_header = $this->get_default_header_sections( 'above-header-layout' );
			$default_below_header = $this->get_default_header_sections( 'below-header-layout' );
			/**
			 * Set metabox options
			 *
			 * @see https://php.net/manual/en/filter.filters.sanitize.php
			 */
			self::$meta_option = apply_filters(
				'astra_advanced_headers_meta_box_options',
				array(
					'ast-advanced-headers-layout'    => array(
						'default'  => array(
							'layout'                     => 'advanced-headers-layout-2',
							'breadcrumb'                 => '',
							'force-transparent-disabled' => 'yes',
							'above-header-enabled'       => $default_above_header,
							'below-header-enabled'       => $default_below_header,
						),
						'sanitize' => 'FILTER_DEFAULT',
					),
					'ast-advanced-headers-design'    => array(
						'default'  => array(
							'title-color'                  => '#ffffff',
							'b-text-color'                 => '',
							'b-link-color'                 => '',
							'b-link-hover-color'           => '',
							'background-color'             => 'rgba(44,62,80,0.50)',
							'bg-image-id'                  => '',
							'bg-image'                     => '',
							'page-post-featured'           => 'enabled',
							'logo-id'                      => '',
							'logo-url'                     => '',
							'retina-logo-id'               => '',
							'retina-logo-url'              => '',
							'header-logo-width'            => '',
							'header-bg-color'              => '',
							'site-title-color'             => '',
							'site-title-h-color'           => '',
							'site-tagline-color'           => '',
							'primary-menu-bg-color'        => '',
							'primary-menu-color'           => '',
							'primary-menu-h-color'         => '',
							'primary-menu-a-color'         => '',
							'primary-submenu-bg-color'     => '',
							'primary-submenu-color'        => '',
							'primary-submenu-h-color'      => '',
							'primary-submenu-a-color'	   => '',

							'above-header-bg-color'        => '',
							'above-header-text-link-color' => '',
							'above-header-h-color'         => '',
							'above-header-a-color'         => '',
							'above-header-submenu-bg-color' => '',
							'above-header-submenu-link-color' => '',
							'above-header-submenu-h-color' => '',
							'above-header-submenu-a-color' => '',

							'below-header-bg-color'        => '',
							'below-header-text-link-color' => '',
							'below-header-h-color'         => '',
							'below-header-a-color'         => '',
							'below-header-submenu-bg-color'=> '',
							'below-header-submenu-link-color' => '',
							'below-header-submenu-h-color' => '',
							'below-header-submenu-a-color' => '',

							'header-main-sep'              => '',
							'header-main-sep-color'        => '',
							'bg-size'                      => 'custom-bg-size',
							'bg-custom-size-top-padding'   => '5',
							'bg-custom-size-bottom-padding' => '5',
							'parallax-device'              => 'none',
							'overlay-bg-color'             => '',
							'custom-menu'                  => '',
							'custom-menu-item'             => 'default',
							'custom-menu-item-outside'     => '',
							'custom-menu-item-text-html'   => '',
							'search-style'                 => 'default',
						),
						'sanitize' => 'FILTER_DEFAULT',
					),
					'ast-advanced-headers-location'  => array(
						'default'  => array(),
						'sanitize' => 'FILTER_DEFAULT',
					),
					'ast-advanced-headers-exclusion' => array(
						'default'  => array(),
						'sanitize' => 'FILTER_DEFAULT',
					),
					'ast-advanced-headers-users'     => array(
						'default'  => array(),
						'sanitize' => 'FILTER_DEFAULT',
					),
				)
			);
		}