Parses <Requirement>

        @param node: Node containing the <Requirement> element
        @type node: xml.etree.Element

def parse_requirement(self, node):
        """
        Parses <Requirement>

        @param node: Node containing the <Requirement> element
        @type node: xml.etree.Element
        """

        if 'name' in node.lattrib:
            name = node.lattrib['name']
        else:
            self.raise_error('<Requirement> must specify a name')

        if 'dimension' in node.lattrib:
            dimension = node.lattrib['dimension']
        else:
            self.raise_error("Requirement \{0}' must specify a dimension.", name)

        self.current_component_type.add_requirement(Requirement(name, dimension))