def __init__(self, uri, root_path=None, contents={}, parser=None, error=None):
    self.uri = uri
    self.root_path = root_path
    self.error = error
    self.parser = parser
    self.contents = contents
def __init__(self, uri, root_path=None, contents={}, parser=None, error=None):
    self.uri = uri
    self.root_path = root_path
    self.error = error
    self.parser = parser
    self.contents = contents