code: def load_nation(fpath):
      cols_names = ["N_NATIONKEY", "N_NAME", "N_REGIONKEY", "N_COMMENT"]
      cols = {
          "N_NATIONKEY": np.int64,
          "N_NAME": str,
          "N_REGIONKEY": np.int64,
          "N_COMMENT": str,
      }
      rel = pd.read_csv(
          fpath, sep="|", header=None, names=cols_names, dtype=cols
      )
      return rel
  
file_path: mars/benchmarks/tpch/loader.py
imports: import numpy
  import pandas
label_desc: Use image node_id 7 for calling a global function with example usage: load_nation(fpath) and returns: rel