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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_generic(lines, element, printed, spacer=""):
 """Generically formats all remaining docstrings and custom XML tags that don't appear in the list of already printed documentation. :arg printed: a list of XML tags for the element that have already been handled by a higher method. """

    for doc in element.docstring:
        if doc.doctype.lower() not in printed:
            lines.append(spacer + doc.__str__())