code: def test_length_one_axis2(self, fill_value, method):
      options = {
          "fill_value": fill_value,
          "bounds_error": False,
          "method": method,
      }
  
      x = cp.linspace(0, 2 * cp.pi, 20)
      z = cp.sin(x)
  
      fa = RegularGridInterpolator((x,), z[:], **options)
      fb = RegularGridInterpolator((x, [0]), z[:, None], **options)
  
      x1a = cp.linspace(-1, 2 * cp.pi + 1, 100)
      za = fa(x1a)
  
      # evaluated at provided y-value, fb should behave exactly as fa
      y1b = cp.zeros(100)
      zb = fb(cp.vstack([x1a, y1b]).T)
      assert_allclose(zb, za)
  
      # evaluated at a different y-value, fb should return fill value
      y1b = cp.ones(100)
      zb = fb(cp.vstack([x1a, y1b]).T)
      if fill_value is None:
          assert_allclose(zb, za)
      else:
          assert_allclose(zb, fill_value)
  
imports: import pytest
  import cupy
  from cupy.testing import assert_allclose, assert_array_equal, assert_array_almost_equal
  from cupy_backends.cuda.api import runtime
  from pytest import raises
  from cupyx.scipy.interpolate import RegularGridInterpolator, interpn
label_desc: Use image node_id 18 for calling the TestRegularGridInterpolator obj's underlying member method code with example usage: obj.test_length_one_axis2(fill_value, method) without return types