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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 _format_object_mask(objectmask):
 """Format the new style object mask. This wraps the user mask with mask[USER_MASK] if it does not already have one. This makes it slightly easier for users. :param objectmask: a string-based object mask """

    objectmask = objectmask.strip()

    if (not objectmask.startswith('mask') and
            not objectmask.startswith('[')):
        objectmask = "mask[%s]" % objectmask
    return objectmask