text: import numpy as np
  from nose.tools import assert_true, assert_equal
  import warnings
  
  from vispy.testing import assert_in
  from vispy.util.fonts import list_fonts, _load_glyph, _vispy_fonts
  
  warnings.simplefilter('always')
  
  
  def test_font_list():
      """Test font listing"""
      f = list_fonts()
      assert_true(len(f) > 0)
      for font in _vispy_fonts:
          assert_in(font, f)
  
  
  def test_font_glyph():
      """Test loading glyphs"""
      # try both a vispy and system font
      for face in ('OpenSans', list_fonts()[0]):
          font_dict = dict(face=face, size=12, bold=False, italic=False)
          glyphs_dict = dict()
          chars = 'foobar^C&#'
          for char in chars:
              # Warning that Arial might not exist
              _load_glyph(font_dict, char, glyphs_dict)
          assert_equal(len(glyphs_dict), np.unique([c for c in chars]).size)
  