def require_dataset(self, name, shape, dtype=None, exact=False, **kwargs):
        """Obtain an array, creating if it doesn't exist. Other `kwargs` are
        as per :func:`zarr.hierarchy.Group.create_dataset`.

        Parameters
        ----------
        name : string
            Array name.
        shape : int or tuple of ints
            Array shape.
        dtype : string or dtype, optional
            NumPy dtype.
        exact : bool, optional
            If True, require `dtype` to match exactly. If false, require
            `dtype` can be cast from array dtype.

        """

        return self._write_op(self._require_dataset_nosync, name, shape=shape,
                              dtype=dtype, exact=exact, **kwargs)
Obtain an array, creating if it doesn't exist. Other `kwargs` are
        as per :func:`zarr.hierarchy.Group.create_dataset`.

        Parameters
        ----------
        name : string
            Array name.
        shape : int or tuple of ints
            Array shape.
        dtype : string or dtype, optional
            NumPy dtype.
        exact : bool, optional
            If True, require `dtype` to match exactly. If false, require
            `dtype` can be cast from array dtype.