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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _try_b32_decode(v):
 """ Attempt to decode a b32-encoded username which is sometimes generated by internal Globus components. The expectation is that the string is a valid ID, username, or b32-encoded name. Therefore, we can do some simple checking on it. If it does not appear to be formatted correctly, return None. """

    # should start with "u_"
    if not v.startswith("u_"):
        return None
    # usernames have @ , we want to allow `u_foo@example.com`
    # b32 names never have @
    if "@" in v:
        return None
    # trim "u_"
    v = v[2:]
    # wrong length
    if len(v) != 26:
        return None

    # append padding and uppercase so that b32decode will work
    v = v.upper() + (6 * "=")

    # try to decode
    try:
        return str(uuid.UUID(bytes=base64.b32decode(v)))
    # if it fails, I guess it's a username? Not much left to do
    except ValueError:
        return None