decimal64 fraction digits sub statement

Hi,

For data type with following yang schema:

typedef pm-data-type {
type union {
type uint64;
type decimal64

{ fraction-digits 2; }

type decimal64

{ fraction-digits 17; }

}
}

ODL is thowing the following error:

java.lang.IllegalArgumentException: Invalid data "-99.9" for union type.
at org.opendaylight.yangtools.yang.data.util.AbstractStringUnionCodec.serialize(AbstractStringUnionCodec.java:47)
at org.opendaylight.yangtools.yang.data.codec.gson.JSONStringUnionCodec.serializeToWriter(JSONStringUnionCodec.java:30)
at org.opendaylight.yangtools.yang.data.codec.gson.JSONNormalizedNodeStreamWriter.writeValue(JSONNormalizedNodeStreamWriter.java:208)
at org.opendaylight.yangtools.yang.data.codec.gson.JSONNormalizedNodeStreamWriter.leafNode(JSONNormalizedNodeStreamWriter.java:98)
at org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeWriter.wasProcessAsSimpleNode(NormalizedNodeWriter.java:152)

can you please help.