nice redefinition of Ruby's Object `to_s` method. If you don't like traversing through the `@parsed` hash every time you call `to_s`, you could save the rate float when you run `api_call`. example:

```ruby
attr_accessor :type, :rate_float

def api_call
  ...
  @rate_float = @parsed["bpi"][@type]["rate_float"]
end
```