code: function disallowed(code) {
    return (
      (code >= 0x0001 && code <= 0x0008) ||
      code === 0x000b ||
      (code >= 0x000d && code <= 0x001f) ||
      (code >= 0x007f && code <= 0x009f) ||
      (code >= 0xfdd0 && code <= 0xfdef) ||
      (code & 0xffff) === 0xffff ||
      (code & 0xffff) === 0xfffe
    )
  }
docs: /* Check if `character` is disallowed.