Format class and class type
  $ refmt ./input.re
  class type _module ('provider_impl) = {};
  type t;
  class type bzz = {
    inherit _module(t);
  };
  
  class type t = {
    as 'a;
    constraint 'a = #s;
  };
  
  /* https://github.com/facebook/reason/issues/2037 */
  class type xt = {
    as 'a;
  };
  
  class x = {
    as self;
  };
  
  class type classWithNoArgType = {
    pub x: int;
    pub y: int;
  };
  
  class classWithNoArg = {
    pub x = 0;
    pub y = 0;
  };
  
  class type t = {
    open M;
    as 'a;
  };
  
  class type t = {
    open M;
  };
