code: def ptr(self):
      return self._ptr
  
imports: import numpy
  import numpy.linalg
  from pycuda.tools import mark_cuda_test, dtype_to_ctype
  import pytest
  import pycuda.gpuarray
  import pycuda.driver
  from pycuda.compiler import SourceModule
label_desc: Use image node_id 3 for calling the CudaArrayInterfaceImpl obj's underlying member method code with example usage: obj.ptr() and returns: self