String Key Type
Values of this type are just a sequence of character, but not an empty sequence.
All printable characters are allowed. There must be at least one such character.
All comparisons are done case-insensitive, i.e.
hell will be the prefix of
To sort two values, the underlying encoding is used to determine which value is less than the other.
Uppercase letters are typically interpreted as less than their corresponding lowercase letters, i.e.
A < a.
Comparison is done character-wise by finding the first difference in the respective character sequence. For example,
abc > aBc.