code: def _fast_dataset(
      variables: 'OrderedDict[Any, Variable]',
      coord_variables: Mapping[Any, Variable],
  ) -> 'Dataset':
      
      from .dataset import Dataset
      variables.update(coord_variables)
      coord_names = set(coord_variables)
      return Dataset._from_vars_and_coord_names(variables, coord_names)
docs: Create a dataset as quickly as possible.
  
      Beware: the `variables` OrderedDict is modified INPLACE.