'Returns the first file in dest that conflicts with src'

def find_conflict(self, dest_root, **kwargs):

    kwargs['follow_nonexisting'] = False
    for (src, dest) in traverse_tree(self._root, dest_root, **kwargs):
        if os.path.isdir(src):
            if (os.path.exists(dest) and (not os.path.isdir(dest))):
                return dest
        elif os.path.exists(dest):
            return dest
    return None
