code: def forward(self, x):
      for blk in self.blocks:
          x = blk(x)
      if self.downsample is not None:
          x = self.downsample(x)
      return x
  
imports: import itertools
  import paddle
  from paddle import nn
  from paddle.nn import functional
  from .common import LayerNorm2d
label_desc: Use image node_id 2 for calling the ConvLayer obj's underlying member method code with example usage: obj.forward(x) and returns: x