docstr: Test SetRectangle.
docstr_tok: ["Test","SetRectangle","."]
code: def test_rectangle(self):
      """Test SetRectangle."""
      self._api.SetImage(self._image)
      self._api.SetRectangle(0, 0, 100, 43)
      thresh = self._api.GetThresholdedImage()
      self.assertEqual(thresh.size, (100, 43))
  
imports: import unittest
  import re
  import os.path
  import tesserocr
label_desc: Use image node_id 13 for calling the TestTessBaseApi obj's underlying member method code with example usage: obj.test_rectangle() without return types