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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 toDom(self):
 """ Generate a DOM representation of the WSDL instance. Not dealing with generating XML Schema, thus the targetNamespace of all XML Schema elements or types used by WSDL message parts needs to be specified via import information items. """

        namespaceURI = DOM.GetWSDLUri(self.version)
        self.document = DOM.createDocument(namespaceURI ,'wsdl:definitions')

        # Set up a couple prefixes for easy reading.
        child = DOM.getElement(self.document, None)
        child.setAttributeNS(None, 'targetNamespace', self.targetNamespace)
        child.setAttributeNS(XMLNS.BASE, 'xmlns:wsdl', namespaceURI)
        child.setAttributeNS(XMLNS.BASE, 'xmlns:xsd', 'http://www.w3.org/1999/XMLSchema')
        child.setAttributeNS(XMLNS.BASE, 'xmlns:soap', 'http://schemas.xmlsoap.org/wsdl/soap/')
        child.setAttributeNS(XMLNS.BASE, 'xmlns:tns', self.targetNamespace)
        
        if self.name:
            child.setAttributeNS(None, 'name', self.name)

        # wsdl:import
        for item in self.imports: 
            item.toDom()
        # wsdl:message
        for item in self.messages:
            item.toDom()
        # wsdl:portType
        for item in self.portTypes:
            item.toDom()
        # wsdl:binding
        for item in self.bindings:
            item.toDom()
        # wsdl:service
        for item in self.services:
            item.toDom()