code: def __test_dict(self):
      buf = self.parse_opts("ndim=3, dtype=unsigned short int")
      self.assertTrue(isinstance(buf.dtype_node, CSimpleBaseTypeNode))
      self.assertTrue(
          buf.dtype_node.signed == 0 and buf.dtype_node.longness == -1
      )
      self.assertEqual(3, buf.ndim)
  
imports: from Cython.TestUtils import CythonTest
  import Cython.Compiler.Errors
  from Cython.Compiler.Nodes import *
  from Cython.Compiler.ParseTreeTransforms import *
  from Cython.Compiler.Buffer import *
label_desc: Use image node_id 5 for calling the TestBufferOptions obj's underlying member method code with example usage: obj.__test_dict() without return types