code: def test_single_subplot(self):
      s = Subplots({}, {}, {})
      f = s.init_figure({}, {})
  
      assert len(s) == 1
      for i, e in enumerate(s):
          for side in ["left", "right", "bottom", "top"]:
              assert e[side]
          for dim in ["col", "row"]:
              assert e[dim] is None
          for axis in "xy":
              assert e[axis] == axis
          assert e["ax"] == f.axes[i]
  
imports: import itertools
  import numpy
  import pytest
  from seaborn._core.subplots import Subplots
label_desc: Use image node_id 1 for calling the TestSubplotElements obj's underlying member method code with example usage: obj.test_single_subplot() without return types