Remove redundant `return`.
Omit the parentheses in defs when the method doesn't accept any arguments.
Use %w if no string interpolation needed.
Remove assigned but unused variable.
Use &:to_s as an argument to map instead of a block.
Use do-end block for multi-line codes.
Merge pull request #2 from larrylv/use-ruby-idiom

Use ruby idiom
Remove tailing whitespaces.