How to use the johnnydep.compat.oyaml function in johnnydep

fields = ("pinned",)
        data = [OrderedDict([(f, getattr(self, f, None)) for f in fields])]
        if format == "human":
            table = gen_table(self, extra_cols=fields)
            tabulate.PRESERVE_WHITESPACE = True
            return tabulate.tabulate(table, headers="keys")
        if recurse and self.requires:
            deps = flatten_deps(self)
            next(deps)  # skip over root
            data += [d for dep in deps for d in dep.serialise(fields=fields, recurse=False)]
        if format is None or format == "python":
            result = data
        elif format == "json":
            result = json.dumps(data, indent=2, default=str, separators=(",", ": "))
        elif format == "yaml":
            result = oyaml.dump(data)
        elif format == "toml":
            result = "\n".join([toml.dumps(d) for d in data])
        elif format == "pinned":
            result = "\n".join([d["pinned"] for d in data])
        else:
            raise Exception("Unsupported format")
        return result