Copy DocstringMeta from another instance.

def from_meta(cls, meta, meta_all=None):
        """Copy DocstringMeta from another instance."""
        if len(meta.args) == 2:
            name = meta.args[1]
            meta_type = None
            for x in meta_all:
                if x.args[1] == name and x.args[0] == 'type':
                    meta_type = x.description
                    break

            return cls(args=meta.args, description=meta.description, type=meta_type)
        else:
            return cls(args=meta.args, description=meta.description)