code: def _load_tsv_knowledge_graph(dataset):
      dataset.download()
  
      train, test, valid = [
          pd.read_csv(
              dataset._resolve_path(name),
              sep="\t",
              names=["source", "label", "target"],
          )
          for name in dataset.expected_files
      ]
  
      all_data = pd.concat([train, test, valid], ignore_index=True)
  
      return (
          StellarDiGraph(edges=all_data, edge_type_column="label"),
          train,
          test,
          valid,
      )
  
imports: from .dataset_loader import DatasetLoader
  from ..core.graph import StellarGraph, StellarDiGraph
  import itertools
  import logging
  import os
  import pandas
  import numpy
  from sklearn import preprocessing
  from ..core.experimental import experimental
label_desc: Use image node_id 3 for calling a global function with example usage: _load_tsv_knowledge_graph(dataset) and returns: StellarDiGraph,  train,  test,  valid