get_option returns false causing array warnings

/**
 * Retrieves WP OAuth Server settings
 *
 * @param  [type] $key [description]
 *
 * @return [type]      [description]
 */
function wo_setting( $key = null ) {

	$default_settings = _WO()->defualt_settings;
	$settings         = get_option( 'wo_options' );
	$settings         = array_merge( $default_settings, array_filter( $settings, function ( $value ) {
		return $value !== '';
	} ) );

This code throws warnings whenever get_option returns false, meaning the option did not already exist. This is a valid use case for the get_option function. The array_filter then throws a warning as you’re passing a boolean to a function that accepts an array. After that, array_merge throws another warning as you’re then passing that same boolean to it when it expects an array.