code: def test_type_E():
      c = CartanType("E6")
      m = Matrix(
          6,
          6,
          [
              2,
              0,
              -1,
              0,
              0,
              0,
              0,
              2,
              0,
              -1,
              0,
              0,
              -1,
              0,
              2,
              -1,
              0,
              0,
              0,
              -1,
              -1,
              2,
              -1,
              0,
              0,
              0,
              0,
              -1,
              2,
              -1,
              0,
              0,
              0,
              0,
              -1,
              2,
          ],
      )
      assert c.cartan_matrix() == m
      assert c.dimension() == 8
      assert c.simple_root(6) == [0, 0, 0, -1, 1, 0, 0, 0]
      assert c.roots() == 72
      assert c.basis() == 78
      diag = (
          " " * 8
          + "2\n"
          + " " * 8
          + "0\n"
          + " " * 8
          + "|\n"
          + " " * 8
          + "|\n"
      )
      diag += "---".join("0" for i in range(1, 6)) + "\n"
      diag += "1   " + "   ".join(str(i) for i in range(3, 7))
      assert c.dynkin_diagram() == diag
      posroots = c.positive_roots()
      assert posroots[8] == [1, 0, 0, 0, 1, 0, 0, 0]
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_type_E() without return types