How to use the hvplot.util.check_library function in hvplot

.relabel(**self._relabel).opts(**opts))

        labelled = ['y' if self.invert else 'x'] if self.group_label != 'Group' else []
        if self.value_label != 'value':
            labelled.append('x' if self.invert else 'y')

        if 'xlabel' in self._plot_opts and 'x' not in labelled:
            labelled.append('x')
        if 'ylabel' in self._plot_opts and 'y' not in labelled:
            labelled.append('y')

        opts['plot']['labelled'] = labelled

        kdims = [self.group_label]
        data = data[list(y)]
        if check_library(data, 'dask'):
            from dask.dataframe import melt
        else:
            melt = pd.melt
        df = melt(data, var_name=self.group_label, value_name=self.value_label)
        redim = self._merge_redim({self.value_label: ylim})
        return (element(df, kdims, self.value_label).redim(**redim)
                .relabel(**self._relabel).opts(**opts))

if 'xlabel' in self._plot_opts and 'x' not in labelled:
            labelled.append('x')
        if 'ylabel' in self._plot_opts and 'y' not in labelled:
            labelled.append('y')

        opts = {'plot': dict(self._plot_opts, labelled=labelled),
                'style': dict(self._style_opts),
                'norm': self._norm_opts}

        id_vars = [x]
        if any(v in self.indexes for v in id_vars):
            data = data.reset_index()
        data = data[y+[x]]

        if check_library(data, 'dask'):
            from dask.dataframe import melt
        else:
            melt = pd.melt

        df = melt(data, id_vars=[x], var_name=self.group_label, value_name=self.value_label)
        kdims = [x, self.group_label]
        vdims = [self.value_label]+self.hover_cols
        if self.subplots:
            obj = Dataset(df, kdims, vdims).to(element, x).layout()
        else:
            obj = element(df, kdims, vdims)
        return (obj.redim(**self._redim)
                .relabel(**self._relabel).opts(**opts))