code: def CartanMatrix(ct):
      """Access the Cartan matrix of a specific Lie algebra
  
      Examples
      ========
  
      >>> from sympy.liealgebras.cartan_matrix import CartanMatrix
      >>> CartanMatrix("A2")
      Matrix([
      [ 2, -1],
      [-1,  2]])
  
      >>> CartanMatrix(['C', 3])
      Matrix([
      [ 2, -1,  0],
      [-1,  2, -1],
      [ 0, -2,  2]])
  
      This method works by returning the Cartan matrix
      which corresponds to Cartan type t.
      """
  
      return CartanType(ct).cartan_matrix()
  
label_desc: Use image node_id 1 for calling a global function with example usage: CartanMatrix(ct) and returns: CartanType