code: def test_negative_longitudes(self):
      longitudes = [-10.0, -15.0, -20.0]
      lower, upper = longitude_bounds(longitudes)
      assert -25.0 < lower < -15.0
      assert -15.0 < upper < -5.0
  
imports: import unittest
  import numpy
  from ..bounds import latitude_bounds, longitude_bounds, merge_longitude_bounds, MAX_ALLOWED_LATITUDE, MIN_ALLOWED_LATITUDE, EPSILON
label_desc: Use image node_id 3 for calling the LongitudeBounds obj's underlying member method code with example usage: obj.test_negative_longitudes() without return types