def __init__(self,
                 cfg,
                 ch_in,
                 ch_out,
                 act,
                 norm_type,
                 name,
                 data_format='NCHW'):
        """
        PPYOLODetBlockCSP layer

        Args:
            cfg (list): layer configs for this block
            ch_in (int): input channel
            ch_out (int): output channel
            act (str): default mish
            name (str): block name
            data_format (str): data format, NCHW or NHWC
        """
        super(PPYOLODetBlockCSP, self).__init__()
        self.data_format = data_format
        self.conv1 = ConvBNLayer(
            ch_in,
            ch_out,
            1,
            padding=0,
            act=act,
            norm_type=norm_type,
            name=name + '.left',
            data_format=data_format)
        self.conv2 = ConvBNLayer(
            ch_in,
            ch_out,
            1,
            padding=0,
            act=act,
            norm_type=norm_type,
            name=name + '.right',
            data_format=data_format)
        self.conv3 = ConvBNLayer(
            ch_out * 2,
            ch_out * 2,
            1,
            padding=0,
            act=act,
            norm_type=norm_type,
            name=name,
            data_format=data_format)
        self.conv_module = nn.Sequential()
        for idx, (layer_name, layer, args, kwargs) in enumerate(cfg):
            kwargs.update(name=name + layer_name, data_format=data_format)
            self.conv_module.add_sublayer(layer_name, layer(*args, **kwargs))

        PPYOLODetBlockCSP layer

        Args:
            cfg (list): layer configs for this block
            ch_in (int): input channel
            ch_out (int): output channel
            act (str): default mish
            name (str): block name
            data_format (str): data format, NCHW or NHWC
        
ppdet/modeling/necks/yolo_fpn.py