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

        if not sctx.schema_data.if_features(stmt, sctx.text_mid):
            return
        id = (stmt.argument, sctx.schema_data.namespace(sctx.text_mid))
        adj = sctx.schema_data.identity_adjs.setdefault(id, IdentityAdjacency())
        for bst in stmt.find_all("base"):
            bid = sctx.schema_data.translate_pname(bst.argument, sctx.text_mid)
            adj.bases.add(bid)
            badj = sctx.schema_data.identity_adjs.setdefault(
                bid, IdentityAdjacency())
            badj.derivs.add(id)
        sctx.schema_data.identity_adjs[id] = adj