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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _replace( # type: ignore self: T, variables: 'OrderedDict[Any, Variable]' = None, coord_names: set = None, dims: Dict[Any, int] = None, attrs: 'Optional[OrderedDict]' = __default, indexes: 'Optional[OrderedDict[Any, pd.Index]]' = __default, encoding: Optional[dict] = __default, inplace: bool = False, ) -> T: """Fastpath constructor for internal use. Returns an object with optionally with replaced attributes. Explicitly passed arguments are *not* copied when placed on the new dataset. It is up to the caller to ensure that they have the right type and are not used elsewhere. """

        if inplace:
            if variables is not None:
                self._variables = variables
            if coord_names is not None:
                self._coord_names = coord_names
            if dims is not None:
                self._dims = dims
            if attrs is not self.__default:
                self._attrs = attrs
            if indexes is not self.__default:
                self._indexes = indexes
            if encoding is not self.__default:
                self._encoding = encoding
            obj = self
        else:
            if variables is None:
                variables = self._variables.copy()
            if coord_names is None:
                coord_names = self._coord_names.copy()
            if dims is None:
                dims = self._dims.copy()
            if attrs is self.__default:
                attrs = copy.copy(self._attrs)
            if indexes is self.__default:
                indexes = copy.copy(self._indexes)
            if encoding is self.__default:
                encoding = copy.copy(self._encoding)
            obj = self._construct_direct(
                variables, coord_names, dims, attrs, indexes, encoding)
        return obj