Create a new Dataset with the listed variables from this dataset and
        the all relevant coordinates. Skips all validation.

def _copy_listed(self: T, names) -> T:
        """Create a new Dataset with the listed variables from this dataset and
        the all relevant coordinates. Skips all validation.
        """
        variables = OrderedDict()  # type: OrderedDict[Any, Variable]
        coord_names = set()
        indexes = OrderedDict()  # type: OrderedDict[Any, pd.Index]

        for name in names:
            try:
                variables[name] = self._variables[name]
            except KeyError:
                ref_name, var_name, var = _get_virtual_variable(
                    self._variables, name, self._level_coords, self.dims)
                variables[var_name] = var
                if ref_name in self._coord_names or ref_name in self.dims:
                    coord_names.add(var_name)
                if (var_name,) == var.dims:
                    indexes[var_name] = var.to_index()

        needed_dims = set()  # type: set
        for v in variables.values():
            needed_dims.update(v.dims)

        dims = dict((k, self.dims[k]) for k in needed_dims)

        for k in self._coord_names:
            if set(self.variables[k].dims) <= needed_dims:
                variables[k] = self._variables[k]
                coord_names.add(k)
                if k in self.indexes:
                    indexes[k] = self.indexes[k]

        return self._replace(variables, coord_names, dims, indexes=indexes)