code: func (e *Entity) F64(path ...string) (F64, error) {
  	lit, err := e.Literal(path...)
  	if err != nil {
  		return 0, errors.Wrap(err, "getting literal")
  	}
  	f64, ok := lit.(F64)
  	if !ok {
  		return 0, errors.Wrapf(ErrUnexpectedType, "%#v not a float64", lit)
  	}
  	return f64, nil
  }
docs: // F64 tries to get a float64 at the given path in the Entity.