:sig
String expand_path(String path, String relative_to_path = "")

:params
path : a relative path
relative_to_path : optional, expand relative to this path (if not given, the current path is used)
return value : expanded version of the 'path'

:see
>sys

:content
Converts a relative path name into an absolute path, using the current working directory as a base when `relative_to_path` is not provided.

## Related Concepts

- PHP: `realpath()` and application-specific path normalization helpers
- JavaScript / Node.js: Node `path.resolve()` and `path.normalize()`