Assertion failed
assert(text != null && (text.length == 1 || text.toLowerCase() == text))
       |    |           |    |      |       |    |             |  |
       |    |           |    |      |       |    |             |  Hello
       |    |           |    |      |       |    |             false
       |    |           |    |      |       |    hello
       |    |           |    |      |       Hello
       |    |           |    |      false
       |    |           |    5
       |    |           Hello
       |    true
       Hello