Collate allows reordering nested containers

        Collation allows collapsing nested mapping types by merging
        their dimensions. In simple terms in merges nested containers
        into a single merged type.

        In the simple case a HoloMap containing other HoloMaps can
        easily be joined in this way. However collation is
        particularly useful when the objects being joined are deeply
        nested, e.g. you want to join multiple Layouts recorded at
        different times, collation will return one Layout containing
        HoloMaps indexed by Time. Changing the merge_type will allow
        merging the outer Dimension into any other UniformNdMapping
        type.

        Args:
            merge_type: Type of the object to merge with
            drop: List of dimensions to drop
            drop_constant: Drop constant dimensions automatically

        Returns:
            Collated Layout or HoloMap

def collate(self, merge_type=None, drop=[], drop_constant=False):
        """Collate allows reordering nested containers

        Collation allows collapsing nested mapping types by merging
        their dimensions. In simple terms in merges nested containers
        into a single merged type.

        In the simple case a HoloMap containing other HoloMaps can
        easily be joined in this way. However collation is
        particularly useful when the objects being joined are deeply
        nested, e.g. you want to join multiple Layouts recorded at
        different times, collation will return one Layout containing
        HoloMaps indexed by Time. Changing the merge_type will allow
        merging the outer Dimension into any other UniformNdMapping
        type.

        Args:
            merge_type: Type of the object to merge with
            drop: List of dimensions to drop
            drop_constant: Drop constant dimensions automatically

        Returns:
            Collated Layout or HoloMap
        """
        from .element import Collator
        merge_type=merge_type if merge_type else self.__class__
        return Collator(self, merge_type=merge_type, drop=drop,
                        drop_constant=drop_constant)()