code: def test_data_storage(self):
      data = np.zeros(100)
      B = Buffer(data=data)
      B.set_data(data=data[:50], copy=False)
      glir_cmd = B._glir.clear()[-1]
      assert glir_cmd[-1].base is data
  
imports: import unittest
  import numpy
  from vispy.testing import run_tests_if_main
  from vispy.gloo.buffer import Buffer, DataBuffer, DataBufferView, VertexBuffer, IndexBuffer
label_desc: Use image node_id 3 for calling the BufferTest obj's underlying member method code with example usage: obj.test_data_storage() without return types