human
Complete this python program:
def fake_paths_lookup(path_dict):
assistant
#Here is the Python code you requested.

    """Usage:
    >>> paths = {\my.txt\: True, \no.txt\: False}
    >>> with fake_paths_lookup(paths):
    ...     assert os.path.exists(\my.txt\) == True
    ...     assert os.path.exists(\no.txt\) == False
    """
    def check(path):
        return path_dict.get(path, None)
    return fake_paths(check)