code: def test_setitem_half(self):
      dtype = np.dtype(
          [
              ("position", np.float32, 3),
              ("texcoord", np.float32, 2),
              ("color", np.float32, 4),
          ]
      )
      data1 = np.zeros(10, dtype=dtype)
      data2 = np.ones(10, dtype=dtype)
      B = DataBuffer(data1)
      B._glir.clear()
      B[:5] = data2[:5]
      glir_cmds = B._glir.clear()
      assert len(glir_cmds) == 1
      set_data = glir_cmds[0][-1]
      assert np.allclose(set_data["position"], data2["position"][:5])
      assert np.allclose(
          set_data["texcoord"][:5], data2["texcoord"][:5]
      )
      assert np.allclose(set_data["color"][:5], data2["color"][:5])
  
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 15 for calling the DataBufferTest obj's underlying member method code with example usage: obj.test_setitem_half() without return types