code: def test_identity(lat, lon, slantrange, az):
      lat1, lon1 = vincenty.vreckon(lat, lon, slantrange, az)
  
      dist, az1 = vincenty.vdist(lat, lon, lat1, lon1)
  
      assert dist == approx(slantrange)
      assert az1 == approx(az)
  
imports: import pymap3d.vincenty
  import pytest
  from pytest import approx
label_desc: Use image node_id 3 for calling a global function with example usage: test_identity(lat, lon, slantrange, az) without return types