Astra_Meta_Boxes::save_meta_box( number $post_id )

		public function save_meta_box( $post_id ) {

			// Checks save status.
			$is_autosave = wp_is_post_autosave( $post_id );
			$is_revision = wp_is_post_revision( $post_id );

			$is_valid_nonce = ( isset( $_POST['astra_settings_meta_box'] ) && wp_verify_nonce( sanitize_text_field( wp_unslash( $_POST['astra_settings_meta_box'] ) ), basename( __FILE__ ) ) ) ? true : false;

			// Exits script depending on save status.
			if ( $is_autosave || $is_revision || ! $is_valid_nonce ) {
				return;
			}

			/**
			 * Get meta options
			 */
			$post_meta = self::get_meta_option();

			foreach ( $post_meta as $key => $data ) {

				// Sanitize values.
				$sanitize_filter = ( isset( $data['sanitize'] ) ) ? $data['sanitize'] : 'FILTER_DEFAULT';

				switch ( $sanitize_filter ) {

					case 'FILTER_SANITIZE_STRING':
							$meta_value = filter_input( INPUT_POST, $key, FILTER_SANITIZE_STRING );
						break;

					case 'FILTER_SANITIZE_URL':
							$meta_value = filter_input( INPUT_POST, $key, FILTER_SANITIZE_URL );
						break;

					case 'FILTER_SANITIZE_NUMBER_INT':
							$meta_value = filter_input( INPUT_POST, $key, FILTER_SANITIZE_NUMBER_INT );
						break;

					default:
							$meta_value = filter_input( INPUT_POST, $key, FILTER_DEFAULT );
						break;
				}

				// Store values.
				if ( $meta_value ) {
					update_post_meta( $post_id, $key, $meta_value );
				} else {
					delete_post_meta( $post_id, $key );
				}
			}

		}