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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_exchangeinsertion(cls):
 """Return the complete string related to the definition of exchange items to be inserted into the string of the template file. <complexType name="arma_v1_mathitemType"> <element name="setitems"> <complexType name="arma_v1_setitemsType"> <element name="additems"> <element name="getitems"> """

        indent = 1
        subs = [cls.get_mathitemsinsertion(indent)]
        for groupname in ('setitems', 'additems', 'getitems'):
            subs.append(cls.get_itemsinsertion(groupname, indent))
            subs.append(cls.get_itemtypesinsertion(groupname, indent))
        return '\n'.join(subs)