'HelloWorld'
[ 'result' => [ 'string' => 'helloWorld', ], 'php_version' => '7.1.33 Linux x86_64',]
'HELLO WORLD!'
[ 'result' => [ 'string' => 'hELLO WORLD!', ], 'php_version' => '7.1.33 Linux x86_64',]