code: def test_type_F():
      c = CartanType("F4")
      m = Matrix(
          4, 4, [2, -1, 0, 0, -1, 2, -2, 0, 0, -1, 2, -1, 0, 0, -1, 2]
      )
      assert c.cartan_matrix() == m
      assert c.dimension() == 4
      assert c.simple_root(1) == [1, -1, 0, 0]
      assert c.simple_root(2) == [0, 1, -1, 0]
      assert c.simple_root(3) == [0, 0, 0, 1]
      assert c.simple_root(4) == [-S.Half, -S.Half, -S.Half, -S.Half]
      assert c.roots() == 48
      assert c.basis() == 52
      diag = "0---0=>=0---0\n" + "   ".join(str(i) for i in range(1, 5))
      assert c.dynkin_diagram() == diag
      assert c.positive_roots() == {
          1: [1, -1, 0, 0],
          2: [1, 1, 0, 0],
          3: [1, 0, -1, 0],
          4: [1, 0, 1, 0],
          5: [1, 0, 0, -1],
          6: [1, 0, 0, 1],
          7: [0, 1, -1, 0],
          8: [0, 1, 1, 0],
          9: [0, 1, 0, -1],
          10: [0, 1, 0, 1],
          11: [0, 0, 1, -1],
          12: [0, 0, 1, 1],
          13: [1, 0, 0, 0],
          14: [0, 1, 0, 0],
          15: [0, 0, 1, 0],
          16: [0, 0, 0, 1],
          17: [S.Half, S.Half, S.Half, S.Half],
          18: [S.Half, -S.Half, S.Half, S.Half],
          19: [S.Half, S.Half, -S.Half, S.Half],
          20: [S.Half, S.Half, S.Half, -S.Half],
          21: [S.Half, S.Half, -S.Half, -S.Half],
          22: [S.Half, -S.Half, S.Half, -S.Half],
          23: [S.Half, -S.Half, -S.Half, S.Half],
          24: [S.Half, -S.Half, -S.Half, -S.Half],
      }
  
imports: from sympy.liealgebras.cartan_type import CartanType
  from sympy.matrices import Matrix
  from sympy.core.backend import S
label_desc: Use image node_id 1 for calling a global function with example usage: test_type_F() without return types