code: def test_GRCh38():
      mt = hl.balding_nichols_model(
          1, 10, 100, n_partitions=10, reference_genome="GRCh38"
      )
      mt = mt.filter_rows(
          hl.all(mt.locus.contig == "chr1", mt.locus.position < 5)
      )
      assert mt.n_partitions() == 1
  
file_path: hail/hail/python/test/hail/extract_intervals/test_key_prefix.py
imports: import hail
label_desc: Use image node_id 13 for calling a global function with example usage: test_GRCh38() without return types