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