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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 _uses_stmt(self, stmt: Statement, sctx: SchemaContext) -> None: """Handle uses statement."""

        if not sctx.schema_data.if_features(stmt, sctx.text_mid):
            return
        grp, gid = sctx.schema_data.get_definition(stmt, sctx)
        if stmt.find1("when"):
            sn = GroupNode()
            self._add_child(sn)
        else:
            sn = self
        sn._handle_substatements(grp, gid)
        for augst in stmt.find_all("augment"):
            sn._augment_stmt(augst, sctx)
        for refst in stmt.find_all("refine"):
            sn._refine_stmt(refst, sctx)