code: def _rampup_factor(self, epoch, iters, num_iters_per_epoch):
      return min(
          1,
          (epoch * num_iters_per_epoch + iters)
          / (2 * num_iters_per_epoch),
      )
  
imports: from copy import deepcopy
  import torch
  import torch.nn.functional
  from lavis.common.registry import registry
  from lavis.common.utils import get_abs_path
  from lavis.models.albef_models import AlbefBase
  from lavis.models.albef_models.albef_outputs import AlbefIntermediateOutput, AlbefOutput
  from lavis.models.base_model import MomentumDistilationMixin
  from lavis.models.med import BertModel
  from lavis.models.vit import VisionTransformerEncoder
  from torch import nn
  from transformers import BertConfig
label_desc: Use image node_id 2 for calling the AlbefNLVR obj's underlying member method code with example usage: obj._rampup_factor(epoch, iters, num_iters_per_epoch) and returns: min