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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 _handle_substatements(self, stmt: Statement, sctx: SchemaContext) -> None: """Dispatch actions for substatements of `stmt`."""

        for s in stmt.substatements:
            if s.prefix:
                key = (
                    sctx.schema_data.modules[sctx.text_mid].prefix_map[s.prefix][0]
                    + ":" + s.keyword)
            else:
                key = s.keyword
            mname = SchemaNode._stmt_callback.get(key, "_noop")
            method = getattr(self, mname)
            method(s, sctx)