How to use the owslib.etree.etree.SubElement function in OWSLib

- cql: common query language text.  Note this overrides bbox, qtype, keywords

        """

        # construct request
        node0 = etree.Element(util.nspath_eval('csw:Transaction', namespaces))
        node0.set('version', self.version)
        node0.set('service', self.service)
        node0.set(util.nspath_eval('xsi:schemaLocation', namespaces), schema_location)

        validtransactions = ['insert', 'update', 'delete']

        if ttype not in validtransactions:  # invalid transaction
            raise RuntimeError, 'Invalid transaction \'%s\'.' % ttype

        node1 = etree.SubElement(node0, util.nspath_eval('csw:%s' % ttype.capitalize(), namespaces))

        if ttype != 'update':  
            node1.set('typeName', typename)

        if ttype == 'insert':
            if record is None:
                raise RuntimeError, 'Nothing to insert.'
            node1.append(etree.fromstring(record))
 
        if ttype == 'update':
            if record is not None:
                node1.append(etree.fromstring(record))
            else:
                if propertyname is not None and propertyvalue is not None:
                    node2 = etree.SubElement(node1, util.nspath_eval('csw:RecordProperty', namespaces))
                    etree.SubElement(node2, util.nspath_eval('csw:Name', namespaces)).text = propertyname

def _setpropertyisequalto(self, parent, propertyname, literal, matchcase=True):
        """

        construct a PropertyIsEqualTo

        Parameters
        ----------

        - parent: parent etree.Element object
        - propertyname: the PropertyName
        - literal: the Literal value
        - matchcase: whether to perform a case insensitve query (default is True)

        """

        tmp = etree.SubElement(parent, util.nspath_eval('ogc:PropertyIsEqualTo', namespaces))
        if matchcase is False:
            tmp.set('matchCase', 'false')
        etree.SubElement(tmp, util.nspath_eval('ogc:PropertyName', namespaces)).text = propertyname
        etree.SubElement(tmp, util.nspath_eval('ogc:Literal', namespaces)).text = literal

node0.set('outputFormat', format)
            node0.set('version', self.version)
            node0.set('service', self.service)
            node0.set('resultType', resulttype)
            if startposition > 0:
                node0.set('startPosition', str(startposition))
            node0.set('maxRecords', str(maxrecords))        
            node0.set(util.nspath_eval('xsi:schemaLocation', namespaces), schema_location)

            node1 = etree.SubElement(node0, util.nspath_eval('csw:Query', namespaces))
            node1.set('typeNames', typenames)
        
            etree.SubElement(node1, util.nspath_eval('csw:ElementSetName', namespaces)).text = esn

            if any([len(constraints) > 0, cql is not None]): 
                node2 = etree.SubElement(node1, util.nspath_eval('csw:Constraint', namespaces))
                node2.set('version', '1.1.0')
                flt = fes.FilterRequest()
                if len(constraints) > 0:
                    node2.append(flt.setConstraintList(constraints))
                # Now add a CQL filter if passed in
                elif cql is not None:
                    etree.SubElement(node2, util.nspath_eval('csw:CqlText', namespaces)).text = cql
                
            if sortby is not None and isinstance(sortby, fes.SortBy):
                node1.append(sortby.toXML())

            self.request = node0

        self._invoke()
 
        if self.exceptionreport is None:

def toXML(self):
        node0 = etree.Element(util.nspath_eval('ogc:PropertyIsBetween', namespaces))
        etree.SubElement(node0, util.nspath_eval('ogc:PropertyName', namespaces)).text = self.propertyname
        node1 = etree.SubElement(node0, util.nspath_eval('ogc:LowerBoundary', namespaces))
        etree.SubElement(node1, util.nspath_eval('ogc:Literal', namespaces)).text = '%s' % self.lower
        node2 = etree.SubElement(node0, util.nspath_eval('ogc:UpperBoundary', namespaces))
        etree.SubElement(node2, util.nspath_eval('ogc:Literal', namespaces)).text = '%s' % self.upper
        return node0

encodes base OwcContext as dict to atom xml tree
    :param d:
    :return:
    """
    xml = etree.Element("feed", nsmap=ns)
    etree.SubElement(xml, "id").text = d['id']

    spec_reference = [axml_link(do) for do in
                      extract_p('properties.links.profiles', d, [])]
    [xml.append(el) for el in spec_reference if el is not None]

    area_of_interest = extract_p('bbox', d, None)
    if area_of_interest is not None:
        try:
            gml = etree.fromstring(area_of_interest)
            georss = etree.SubElement(xml, ns_elem("georss", "where"))
            georss.append(gml)
        except Exception as ex:
            log.warn('could encode bbox into georss:where', ex)
            pass

    context_metadata = [axml_link(do) for do in
                        extract_p('properties.links.via', d, [])]
    [xml.append(el) for el in context_metadata if el is not None]

    language = extract_p('properties.lang', d, None)
    if language is not None: xml.set(ns_elem("xml", "lang"), language)

    title = extract_p('properties.title', d, None)
    if title is not None: etree.SubElement(xml, "title").text = title

    # 

def setsortby(parent, propertyname, order='ASC'):
    """

    constructs a SortBy element

    Parameters
    ----------

    - parent: parent etree.Element object
    - propertyname: the PropertyName
    - order: the SortOrder (default is 'ASC')

    """

    tmp = etree.SubElement(parent, util.nspath_eval('ogc:SortBy', namespaces))
    tmp2 = etree.SubElement(tmp, util.nspath_eval('ogc:SortProperty', namespaces))
    etree.SubElement(tmp2, util.nspath_eval('ogc:PropertyName', namespaces)).text = propertyname
    etree.SubElement(tmp2, util.nspath_eval('ogc:SortOrder', namespaces)).text = order

dataElement = etree.Element(nspath_eval('wps:Data', namespaces))
        complexDataElement = etree.SubElement(
            dataElement, nspath_eval('wps:ComplexData', namespaces),
            attrib={"mimeType": "text/xml", "schema": GML_SCHEMA_LOCATION})
        featureMembersElement = etree.SubElement(
            complexDataElement, nspath_eval('gml:featureMembers', namespaces),
            attrib={nspath_eval("xsi:schemaLocation", namespaces): "%s %s" % (DRAW_NAMESPACE, DRAW_SCHEMA_LOCATION)})
        boxElement = etree.SubElement(featureMembersElement, nspath_eval(
            'gml:box', namespaces), attrib={nspath_eval("gml:id", namespaces): "box.1"})
        geomElement = etree.SubElement(
            boxElement, nspath_eval('gml:the_geom', namespaces))
        multiPolygonElement = etree.SubElement(
            geomElement, nspath_eval('gml:MultiPolygon', namespaces),
            attrib={"srsDimension": "2", "srsName": "http://www.opengis.net/gml/srs/epsg.xml#4326"})
        for polygon in self.polygons:
            polygonMemberElement = etree.SubElement(
                multiPolygonElement, nspath_eval('gml:polygonMember', namespaces))
            polygonElement = etree.SubElement(
                polygonMemberElement, nspath_eval('gml:Polygon', namespaces))
            exteriorElement = etree.SubElement(
                polygonElement, nspath_eval('gml:exterior', namespaces))
            linearRingElement = etree.SubElement(
                exteriorElement, nspath_eval('gml:LinearRing', namespaces))
            posListElement = etree.SubElement(
                linearRingElement, nspath_eval('gml:posList', namespaces))
            posListElement.text = ' '.join(
                ["%s %s" % (x, y) for x, y in polygon[:]])

        idElement = etree.SubElement(
            boxElement, nspath_eval('gml:ID', namespaces))
        idElement.text = "0"
        return dataElement

#            
        #                the_geom
        #                STATE
        #                
        #                    
        #                
        #            

        queryElement = etree.Element(
            nspath_eval('wfs:Query', namespaces), attrib={"typeName": self.typeName})
        for propertyName in self.propertyNames:
            propertyNameElement = etree.SubElement(
                queryElement, nspath_eval('wfs:PropertyName', namespaces))
            propertyNameElement.text = propertyName
        if len(self.filters) > 0:
            filterElement = etree.SubElement(
                queryElement, nspath_eval('ogc:Filter', namespaces))
            for filter in self.filters:
                # gmlObjectIdElement
                etree.SubElement(
                    filterElement, nspath_eval('ogc:GmlObjectId', namespaces),
                    attrib={nspath_eval('gml:id', namespaces): filter})
        return queryElement

if etree.__name__ != 'lxml.etree':  # apply nsmap manually
                node0.set('xmlns:ows', namespaces['ows'])
                node0.set('xmlns:gmd', namespaces['gmd'])
                node0.set('xmlns:dif', namespaces['dif'])
                node0.set('xmlns:fgdc', namespaces['fgdc'])
            node0.set('outputSchema', outputschema)
            node0.set('outputFormat', format)
            node0.set('version', self.version)
            node0.set('resultType', resulttype)
            node0.set('service', self.service)
            if startposition > 0:
                node0.set('startPosition', str(startposition))
            node0.set('maxRecords', str(maxrecords))
            node0.set(util.nspath_eval('xsi:schemaLocation', namespaces), schema_location)
    
            node1 = etree.SubElement(node0, util.nspath_eval('csw:Query', namespaces))
            node1.set('typeNames', typenames)
        
            etree.SubElement(node1, util.nspath_eval('csw:ElementSetName', namespaces)).text = esn
    
            self._setconstraint(node1, qtype, propertyname, keywords, bbox, cql, None)
    
            if sortby is not None:
                fes.setsortby(node1, sortby)
    
            self.request = node0

        self._invoke()
 
        if self.exceptionreport is None:
            self.results = {}

attrib={"srsDimension": "2", "srsName": "http://www.opengis.net/gml/srs/epsg.xml#4326"})
        for polygon in self.polygons:
            polygonMemberElement = etree.SubElement(
                multiPolygonElement, nspath_eval('gml:polygonMember', namespaces))
            polygonElement = etree.SubElement(
                polygonMemberElement, nspath_eval('gml:Polygon', namespaces))
            exteriorElement = etree.SubElement(
                polygonElement, nspath_eval('gml:exterior', namespaces))
            linearRingElement = etree.SubElement(
                exteriorElement, nspath_eval('gml:LinearRing', namespaces))
            posListElement = etree.SubElement(
                linearRingElement, nspath_eval('gml:posList', namespaces))
            posListElement.text = ' '.join(
                ["%s %s" % (x, y) for x, y in polygon[:]])

        idElement = etree.SubElement(
            boxElement, nspath_eval('gml:ID', namespaces))
        idElement.text = "0"
        return dataElement