code: def test_text3d_source():
      src = pv.Text3DSource(string="Text")
      assert src.string == "Text"
      out = src.output
      assert len(out.split_bodies()) == 4
  
file_path: pyvista/tests/core/test_geometric_sources.py
imports: import numpy
  import pytest
  import vtk
  import pyvista
  from pyvista import examples
  from pyvista.core.utilities.geometric_objects import translate
label_desc: Use image node_id 7 for calling a global function with example usage: test_text3d_source() without return types