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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 dendrogram(adata, groupby, dendrogram_key=None, orientation='top', remove_labels=False, show=None, save=None):
 """Plots a dendrogram of the categories defined in `groupby`. See :func:`~scanpy.tl.dendrogram`. Parameters adata : :class:`~anndata.AnnData` groupby : `str` Categorical data column used to create the dendrogram dendrogram_key : `str`, optional(default: `None`) Key under with the dendrogram information was stored. By default the dendrogram information is stored under .uns['dendrogram_' + groupby]. orientation : `str`, optional(default: `top`) Options are `top`, `bottom`, `left`, and `right`. Only when `show_correlation` is False remove_labels : `bool`, optional(default: `False`) {show_save_ax} Returns ------- Examples -------- """

    fig, ax = pl.subplots()
    _plot_dendrogram(ax, adata, groupby, dendrogram_key=dendrogram_key,
                     remove_labels=remove_labels, orientation=orientation)

    utils.savefig_or_show('dendrogram', show=show, save=save)

    return ax