code: def test_lambda_gc(self):
      N = 5000000
      ht = hl.utils.range_table(N).annotate(
          x=hl.scan.count() / N, x2=(hl.scan.count() / N) ** 1.5
      )
      lgc = hl.lambda_gc(ht.x)
      lgc2 = hl.lambda_gc(ht.x2)
      self.assertAlmostEqual(
          lgc, 1, places=1
      )  # approximate, 1 place is safe
      self.assertAlmostEqual(lgc2, 1.89, places=1)
  
imports: import unittest
  import hail
  from ..helpers import *
label_desc: Use image node_id 16 for calling the Tests obj's underlying member method code with example usage: obj.test_lambda_gc() without return types