code: def __init__(self, length, duration, dim, cfg):
      super(Memory, self).__init__()
      self.length = length
      self.duration = duration
      self.dim = dim
      stdv = 1.0 / math.sqrt(dim / 3)
      self.register_buffer(
          "memory",
          torch.rand(length, duration, dim).mul_(2 * stdv).add_(-stdv),
      )
      self.device = self.memory.device
      self.l2_norm = Normalize(dim=1)
      self.l2_norm2d = Normalize(dim=2)
      self.num_gpus = cfg.NUM_GPUS
  
imports: import math
  import numpy
  import torch
  import torch.nn
  import torch.nn.functional
  import slowfast.models.losses
  import slowfast.utils.distributed
  import slowfast.utils.logging
  from slowfast.models.video_model_builder import X3D, MViT, ResNet, SlowFast
  from .build import MODEL_REGISTRY
label_desc: Use image node_id 1 to create a new Memory object from inherited base classes: nn with example: obj = Memory(length, duration, dim, cfg)