@Override
  public PdxWriter writeChar(String fieldName, char value) {
    updateMetaData(fieldName, FieldType.CHAR);
    os.writeChar(value);
    return this;
  }
If true then extra validation is done to detect if mistakes have been made in the way PdxWriter
is used. Currently this will cause PdxSerializationException to be thrown if the number, names,
or types of fields are changed or if different identity fields are marked on the same instance
of a class. This property should only be set when debugging new code since it will slow down
pdx serialization.
geode-core/src/main/java/org/apache/geode/pdx/internal/PdxWriterImpl.java