code: def _get_classifier_input_dim(self):
      return self.image_text_multi_modal_combine_layer.out_dim
  
imports: import copy
  import omegaconf
  import torch
  from mmf.common.registry import registry
  from mmf.models.base_model import BaseModel
  from mmf.modules.embeddings import ImageFeatureEmbedding, MultiHeadImageFeatureEmbedding, PreExtractedEmbedding, TextEmbedding
  from mmf.modules.layers import ClassifierLayer, ModalCombineLayer
  from mmf.utils.build import build_image_encoder
  from torch import nn
label_desc: Use image node_id 15 for calling the Pythia obj's underlying member method code with example usage: obj._get_classifier_input_dim() and returns: self