Should strip this annotation

[nickretallack]

Output:

class A {
  a: Function;
  a() {}
}

Output:

class A {
  a: Function;

  a() {}
}

It should strip the a: Function; line. If you compile the code with flow, that line gets stripped out of the output, but if you compile it with TypeScript, it acts as a duplicate declaration which overrides the original, resulting in code where a is undefined.