The top level Dotenv module. The entrypoint for the application logic.
same as `load`, but raises Errno::ENOENT if any files don‘t exist
same as `load`, but will override existing values in `ENV`
same as `overload`, but raises Errno::ENOENT if any files don‘t exist
returns a hash of parsed key/value pairs but does not modify ENV
Internal: Helper to expand list of filenames.
Returns a hash of all the loaded environment variables.
[Validate]