def __init__(self, groups=None):
        super(GroupedRequirements, self).__init__(NamedRequirements)
        self.groups = groups or self.default_groups
        self.filename = None
        self.create_default_groups()
def connection_made(self, transport):
        self.transport = transport
        # Here the buffer is intended to be copied, so that the outgoing buffer
        # won't be wrongly updated by next read
        self.buffer = bytearray(256 * 1024)