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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 get_identity(user):
 """Create an identity for a given user instance. Primarily useful for testing. """

    identity = Identity(user.id)

    if hasattr(user, 'id'):
        identity.provides.add(UserNeed(user.id))

    for role in getattr(user, 'roles', []):
        identity.provides.add(RoleNeed(role.name))

    identity.user = user
    return identity