Kata

Instead of having to access values in hash by

h[:one]

or

h["one"]

write a method_missing that allows to use

h._one

both for reading and writing. It should

• first check for a key as a symbol, then for a key as a string
• return nil if neither was found
• return the value upon setting a new one
• add a new key as a symbol if it doesn't exist yet
• update whatever key is there, either symbol or string