text: from mypy.plugin import CallableType, CheckerPluginInterface, MethodSigContext, Plugin
  from mypy.types import Instance, Type
  
  class MethodSigPlugin(Plugin):
      def get_method_signature_hook(self, fullname):
          # Ensure that all names are fully qualified
          assert not fullname.endswith(' of Foo')
  
          if fullname.startswith('__main__.Foo.'):
              return my_hook
  
          return None
  
  def _str_to_int(api: CheckerPluginInterface, typ: Type) -> Type:
      if isinstance(typ, Instance):
          if typ.type.fullname() == 'builtins.str':
              return api.named_generic_type('builtins.int', [])
          elif typ.args:
              return typ.copy_modified(args=[_str_to_int(api, t) for t in typ.args])
  
      return typ
  
  def my_hook(ctx: MethodSigContext) -> CallableType:
      return ctx.default_signature.copy_modified(
          arg_types=[_str_to_int(ctx.api, t) for t in ctx.default_signature.arg_types],
          ret_type=_str_to_int(ctx.api, ctx.default_signature.ret_type),
      )
  
  def plugin(version):
      return MethodSigPlugin
  