code: def test_text3d_source_empty_string():
      # Test empty string is processed to have a single point
      src = pv.Text3DSource(process_empty_string=True)
      assert src.process_empty_string
      out = src.output
      assert out.n_points == 1
  
      # Test setting an empty string is processed to have a single point
      src.process_empty_string = False
      assert not src.process_empty_string
      out = src.output
      assert out.n_points == 0
  
      if pv.vtk_version_info == (9, 0, 3):
          mx, mn = 1, -1
      else:
          mx, mn = vtk.VTK_DOUBLE_MAX, vtk.VTK_DOUBLE_MIN
  
      assert out.bounds == (mx, mn, mx, mn, mx, mn)
  
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 6 for calling a global function with example usage: test_text3d_source_empty_string() without return types