code: def invert(self, src=None):
          
          if src is None:
              dst = TOOLS._invert_matrix(self)
          else:
              dst = TOOLS._invert_matrix(src)
          if dst[0] == 1:
              return 1
          self.a, self.b, self.c, self.d, self.e, self.f = dst[1]
          return 0
docs: Calculate the inverted matrix. Return 0 if successful and replace
          current one. Else return 1 and do nothing.