Retrieves the attribute of the given name from the node.

    If not present then the default_value is used.

def __get_attribute(node, name, default_value=''):
    """Retrieves the attribute of the given name from the node.

    If not present then the default_value is used.
    """
    if node.hasAttribute(name):
        return node.attributes[name].value.strip()
    else:
        return default_value