WP_Customize_Manager::post_value( WP_Customize_Setting $setting, mixed $default_value = null ): string|mixed

1835	public function post_value( $setting, $default_value = null ) {1836		$post_values = $this->unsanitized_post_values();1837		if ( ! array_key_exists( $setting->id, $post_values ) ) {1838			return $default_value;1839		}1840 1841		$value = $post_values[ $setting->id ];1842		$valid = $setting->validate( $value );1843		if ( is_wp_error( $valid ) ) {1844			return $default_value;1845		}1846 1847		$value = $setting->sanitize( $value );1848		if ( is_null( $value ) || is_wp_error( $value ) ) {1849			return $default_value;1850		}1851 1852		return $value;1853	}