docs: def transitive_closure(self):
          """Compute the transitive closure of the matrix."""
          data = [[1 if j else 0 for j in i] for i in self.data]
          for k in range(self.rows):
              for i in range(self.rows):
                  for j in range(self.rows):
                      if data[i][k] and data[k][j]:
                          data[i][j] = 1
          return data