You can pass an $option name to set to $value, an array of $option names to set to $value, or an associative array of $option names and their values to set.
public function testSettingAndUnsettingOptions() { $this->sandbox->setOption('error_level', 1); $this->assertEquals(1, $this->sandbox->getOption('error_level')); $this->sandbox->setOption('error_level', null); $this->assertEquals(null, $this->sandbox->getOption('error_level')); }