private byte[] createBlob(Object o) throws IOException {
    HeapDataOutputStream out = new HeapDataOutputStream(KnownVersion.CURRENT);
    DataSerializer.writeObject(o, out);
    return out.toByteArray();
  }
Init fields using base as appropriate, but does not initialize aQueryObject field.

@param base The base value for all fields. Fields are all set to a value using base as
       appropriate.
@param useNulls If true, fill in nulls for those fields that can be set to null (to test null
       values), if false, then use a valid value (to test non-null values).
geode-core/src/integrationTest/java/org/apache/geode/pdx/PdxSerializableJUnitTest.java