code: def test_insert(sphere):
      multi = MultiBlock({f"{i}": sphere for i in range(3)})
      cube = pv.Cube()
      multi.insert(0, cube)
      assert len(multi) == 4
      assert multi[0] is cube
  
      # test with negative index and name
      multi.insert(-1, pv.ImageData(), name="uni")
      assert len(multi) == 5
      # inserted before last element
      assert isinstance(
          multi[-2], pv.ImageData
      )  # inserted before last element
      assert multi.get_block_name(-2) == "uni"
  
imports: import pathlib
  import platform
  import weakref
  import numpy
  import pytest
  import vtk
  import pyvista
  from pyvista import ImageData, MultiBlock, PolyData, RectilinearGrid, StructuredGrid, examples
label_desc: Use image node_id 13 for calling a global function with example usage: test_insert(sphere) without return types