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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 _get_gosubdagplotnts(self, hdrgo, usrgos, pltargs, go2parentids):
 """Get list of GoSubDagPlotNt for plotting an exploratory GODAG for 1 Group of user GOs."""

        dotgraphs = []
        go2color = pltargs.get_go2color_inst(hdrgo)
        # namedtuple fields: hdrgo gosubdag tot_usrgos parentcnt desc
        ntpltgo0 = self._get_pltdag_ancesters(hdrgo, usrgos, desc="")
        ntpltgo1 = self._get_pltdag_path_hdr(hdrgo, usrgos, desc="pruned")
        num_go0 = len(ntpltgo0.gosubdag.go2obj)
        num_go1 = len(ntpltgo1.gosubdag.go2obj)
        title = "{GO} {NAME}; {N} GO sources".format(
            GO=hdrgo,
            NAME=self.gosubdag.go2obj[hdrgo].name,
            N=len(ntpltgo0.gosubdag.go_sources))
        # print("PltGroupedGos::_get_gosubdagplotnts TITLE", title)
        if num_go0 < pltargs.max_gos:
            # print("PltGroupedGos::_get_gosubdagplotnts ntpltgo0 ALWAYS IF NOT TOO BIG")
            dotgraphs.append(self._get_gosubdagplotnt(ntpltgo0, title, go2color, pltargs))
        # PLOT A: Plot the entire GO ID group under GO header, hdrgo, if not too big
        if num_go0 < pltargs.max_gos and \
            ntpltgo0.tot_usrgos == ntpltgo1.tot_usrgos:
            # print("PltGroupedGos::_get_gosubdagplotnts ntpltgo0 AAAAAAAAAAAAAAAAA")
            dotgraphs.append(self._get_gosubdagplotnt(ntpltgo0, title, go2color, pltargs))
        # PLOT B: Plot only the GO ID group passing thru the GO header, hdrgo, if not too big
        elif num_go1 < pltargs.max_gos and ntpltgo0.tot_usrgos != ntpltgo1.tot_usrgos:
            # print("PltGroupedGos::_get_gosubdagplotnts ntpltgo1(pruned) BBBBBBBBBBBBBBBBB")
            dotgraphs.append(self._get_gosubdagplotnt(ntpltgo1, title, go2color, pltargs))
        # PLOT C: If DAG is large, just print upper portion
        # PLOT D: If DAG is large, just print upper portion passing through the GO header
        elif num_go1 >= pltargs.upper_trigger:
            # print("PltGroupedGos::_get_gosubdagplotnts upper_pruned CCCCCCCCCCCCCCCCC")
            gos_upper = self._get_gos_upper(ntpltgo1, pltargs.max_upper, go2parentids)
            #ntpltgo2 = self._get_pltdag_ancesters(hdrgo, gos_upper, "{BASE}_upper.png")
            ntpltgo3 = self._get_pltdag_path_hdr(hdrgo, gos_upper, "upper_pruned")
            # Middle GO terms chosen to be start points will be green unless reset back
            for goid in gos_upper:
                if goid not in go2color:
                    go2color[goid] = 'white'
            dotgraphs.append(self._get_gosubdagplotnt(ntpltgo3, title, go2color, pltargs))
        else:
            # print("PltGroupedGos::_get_gosubdagplotnts EEEEEEEEEEEEEEEEE")
            self._no_ntplt(ntpltgo0)
        return dotgraphs