Cldr.Map.underscore_keys
You're seeing just the function
underscore_keys, go back to Cldr.Map module for more information.
Convert map String.t keys from camelCase to snake_case
mapis anymap/0optionsis a keyword list of options passed todeep_map/3
Example
iex> Cldr.Map.underscore_keys %{"a" => %{"thisOne" => "value"}}
%{"a" => %{"this_one" => "value"}}