duplicate instance

[root@141179 udpst]# cat /etc/config/udpst/odl/udpst.odl
%populate {
        object 'InternetGatewayDevice' {
                object 'IPLayerCapacityMetrics' {
                        object 'X_ATT_ResultHistory' {
                                instance add(1) {
                                }
                        }
                }
        }
}
[root@141179 udpst]# cat /etc/amx/udpst/udpst.odl
%config {
    name = "udpst";
    import-dbg = true;
    rw_data_path = "/etc/config";
    save_file = "${rw_data_path}/${name}/${name}.odl";

        // Application specific settings
    // persistent storage location
    storage-path = "${rw_data_path}/${name}/";
    //defaults_file = "${name}_defaults.odl";
    odl = {
        load-dm-events = false,
        dm-save = true,
        dm-save-on-changed = true,
        dm-save-delay = 1000,
        directory = "${storage-path}/odl"
    };
    definition_file = "${name}_definition.odl";
    defaults_file = "${name}_defaults.odl";
}

import "${name}.so" as "${name}";

include "udpst_definition.odl";
?include "/etc/config/udpst/odl/udpst.odl":"udpst_defaults.odl";
%define {
    entry-point udpst.udpst_main;
}
[root@141179 udpst]# cat /etc/amx/udpst/udpst_definition.odl
%config {
        import-dbg = true;
}

%define {
    %persistent object InternetGatewayDevice {
        %persistent object IPLayerCapacityMetrics {
            %persistent object X_ATT_ResultHistory[] {
                %read-only string Role;
                %read-only string DiagnosticsState;
            }
        }
    }
}
[root@141179 udpst]# cat /etc/amx/udpst/udpst_defaults.odl
%populate {
    object InternetGatewayDevice.IPLayerCapacityMetrics.X_ATT_ResultHistory {
        instance add (0,"") {
            parameter 'Role' = "Test";
            parameter 'DiagnosticsState' = "Started";
        }
    }
}
[root@141179 udpst]# udpst
[IMPORT-DBG] - dlopen - udpst.so (0x1ca1f60)
[IMPORT-DBG] - symbol _udpst_main resolved (for udpst_main) from udpst
[IMPORT-DBG] - symbols used of udpst = 1
ERROR -- Here No backends specified

RK /usr/bin/mods/amxb/mod-amxb-ubus.so -
ERROR  : 13 - Duplicate instance@/etc/config/udpst/odl/udpst.odl:line 5
xxx 3
^CERROR  : 13 - Duplicate instance@/etc/config/udpst/odl/udpst.odl:line 5
xxx 3