'Converts an xml fragment into a list of scalar types.  The parent xml
element contains a flat list of xml elements which are converted into the
specified scalar type and added to the list.
Example:
xmldoc=
<Endpoints>
<Endpoint>http://{storage-service-name}.blob.core.windows.net/</Endpoint>
<Endpoint>http://{storage-service-name}.queue.core.windows.net/</Endpoint>
<Endpoint>http://{storage-service-name}.table.core.windows.net/</Endpoint>
</Endpoints>
element_type=str
parent_xml_element_name=\'Endpoints\'
xml_element_name=\'Endpoint\''

@staticmethod
def _fill_scalar_list_of(xmldoc, element_type, parent_xml_element_name, xml_element_name):

    xmlelements = _MinidomXmlToObject.get_child_nodes(xmldoc, parent_xml_element_name)
    if xmlelements:
        xmlelements = _MinidomXmlToObject.get_child_nodes(xmlelements[0], xml_element_name)
        return [_MinidomXmlToObject._get_node_value(xmlelement, element_type) for xmlelement in xmlelements]
