src/Growl.php
public function setSafe($options)
    {
        if (is_string($options)) {
            $this->safe[] = $options;
            return $this;
        }

        if (is_array($options)) {
            foreach ($options as $key => $value) {
                $this->safe[] = $value;
            }
            return $this;
        }

        throw new InvalidArgumentException(
            'This method expects a string or an array argument.'
        );
    }
public function setSafe($options)
    {
        if (is_string($options)) {
            $this->safe[] = $options;
            return $this;
        }

        if (is_array($options)) {
            foreach ($options as $key => $value) {
                $this->safe[] = $value;
            }
            return $this;
        }

        throw new InvalidArgumentException(
            'This method expects a string or an array argument.'
        );
    }
Sets option names that are considered safe, in order to bypass escaping.

@param mixed A string or array of option names assumed to be safe from
escaping.
@throws \InvalidArgumentException If the method argument isn't a string or
array.
@return $this