docstr: Clears the `EncodedDs` cache. 
docstr_tok: ["Clears","the","`","EncodedDs","`","cache","."]
code: def clear_cache(self):
      """Clears the `EncodedDs` cache."""
      self.X_cache = torch.full(
          (len(self.data_frame),), fill_value=torch.nan
      )
      self.Y_cache = torch.full(
          (len(self.data_frame),), fill_value=torch.nan
      )
      self.cache_built = False
  
imports: import inspect
  from typing import List, Tuple, Dict
  import torch
  import numpy
  import pandas
  from torch.utils.data import Dataset
  from lightwood.encoder.base import BaseEncoder
label_desc: Use image node_id 9 for calling the EncodedDs obj's underlying member method code with example usage: obj.clear_cache() without return types