Returns a list of all files in the specified directory,
    optionally recursively and/or with the specified extensions.

def list_matching_files(dir, extensions=None, recursive=True):
    """
    Returns a list of all files in the specified directory,
    optionally recursively and/or with the specified extensions.
    """
    from .modules import utils
    return utils.list_matching_files(dir, extensions=extensions, recursive=recursive)