code: def _round_down(num):
      return int(math.floor(num))
  
imports: import collections
  import itertools
  import math
  import numpy
  from third_party.nucleus.util import variant_utils
  from third_party.nucleus.util import variantcall_utils
  from deepvariant import vcf_stats_vis
label_desc: Use image node_id 10 for calling a global function with example usage: _round_down(num) and returns: int