public function testLower() { $plugin = new BasicPlugin(); $result = $plugin->callFilter('lower', 'FOO'); $this->assertEquals('foo', $result); ob_start(); $result = $plugin->callFunction('var_dump', ['FOO']); $contents = ob_get_contents(); ob_end_clean(); $result = $plugin->callFunction('memory_usage', []); $this->assertGreaterThan(0, strlen($result)); }