added functionality to plot

        mask[mask] = self.suppression.mask

        self.masks = ('suppression', mask)

    def plot_source(self, ax=None, clean_keys=[], **kwargs):

    def plot_source(self, ax=None, clean_keys=[], **kwargs):  # pragma: no cover

        matches, mask = self.clean(clean_keys=clean_keys)

        indices = pd.Index(matches['source_idx'].values)

        return plot_node(self.source, ax=ax, index_mask=indices, **kwargs)

        return plot_node(self.source, index_mask=indices, **kwargs)

    def plot_destination(self, ax=None, clean_keys=[], **kwargs):

    def plot_destination(self, ax=None, clean_keys=[], **kwargs):  # pragma: no cover

        matches, mask = self.clean(clean_keys=clean_keys)

        indices = pd.Index(matches['destination_idx'].values)

        return plot_node(self.destination, ax=ax, index_mask=indices, **kwargs)

        return plot_node(self.destination, index_mask=indices, **kwargs)

    def plot(self, ax=None, clean_keys=[], **kwargs):

    def plot(self, ax=None, clean_keys=[], node=None, **kwargs):

        dest_keys = [0, '0', 'destination', 'd', 'dest']

        source_keys = [1, '1', 'source', 's']

        # If node is not none, plot a single node

        if node in source_keys:

            return self.plot_source(self, clean_keys=clean_keys, **kwargs)

        elif node in dest_keys:

            return self.plot_destination(self, clean_keys=clean_keys, **kwargs)

        # Else, plot the whole edge

        return plot_edge(self, ax=ax, clean_keys=clean_keys, **kwargs)

    def clean(self, clean_keys, pid=None):