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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 valid_name(name):
    "Validate a cookie name string"
    if isinstance(name, bytes):
        name = name.decode('ascii')
    if not Definitions.COOKIE_NAME_RE.match(name):
        return False
    # This module doesn't support $identifiers, which are part of an obsolete
    # and highly complex standard which is never used.
    if name[0] == "$":
        return False
    return True