code: def test_sinc():
      x = Symbol("x")
      lines = [
          "      1 |                          . .                          ",
          "        |                         .   .                         ",
          "        |                                                       ",
          "        |                        .     .                        ",
          "        |                                                       ",
          "        |                       .       .                       ",
          "        |                                                       ",
          "        |                                                       ",
          "        |                      .         .                      ",
          "        |                                                       ",
          "    0.4 |-------------------------------------------------------",
          "        |                     .           .                     ",
          "        |                                                       ",
          "        |                    .             .                    ",
          "        |                                                       ",
          "        |    .....                                     .....    ",
          "        |  ..     \\         .               .         /     ..  ",
          "        | /        \\                                 /        \\ ",
          "        |/          \\      .                 .      /          \\",
          "        |            \\    /                   \\    /            ",
          "   -0.2 |_______________________________________________________",
          "         -10                        0                          10",
      ]
      # RuntimeWarning: invalid value encountered in double_scalars
      with ignore_warnings(RuntimeWarning):
          assert lines == list(textplot_str(sin(x) / x, -10, 10))
  
file_path: sympy/sympy/plotting/tests/test_textplot.py
imports: from sympy.core.singleton import S
  from sympy.core.symbol import Symbol
  from sympy.functions.elementary.exponential import log
  from sympy.functions.elementary.miscellaneous import sqrt
  from sympy.functions.elementary.trigonometric import sin
  from sympy.plotting.textplot import textplot_str
  from sympy.utilities.exceptions import ignore_warnings
label_desc: Use image node_id 3 for calling a global function with example usage: test_sinc() without return types