code: private boolean validateCompatibleWithTableOccVersion(
        EntitySchema entitySchema1, EntitySchema entitySchema2) {
      boolean foundOccMapping = false;
      for (FieldMapping fieldMapping : entitySchema1.getColumnMappingDescriptor()
          .getFieldMappings()) {
        if (fieldMapping.getMappingType() == MappingType.OCC_VERSION) {
          foundOccMapping = true;
          break;
        }
      }
      if (foundOccMapping) {
        for (FieldMapping fieldMapping : entitySchema2
            .getColumnMappingDescriptor().getFieldMappings()) {
          if (fieldMapping.getMappingType() == MappingType.OCC_VERSION) {
            LOG.warn("Field: " + fieldMapping.getFieldName() + " in schema "
                + entitySchema2.getName()
                + " conflicts with an occVersion field in "
                + entitySchema1.getName());
            return false;
          }
        }
      }
      return true;
    }
docs: Only one schema for a table should contain an OCCVersion field mapping.
  This method will compare two schemas and return true if only one has an
  OCC_VERSION field.
  
  @param entitySchema1
  The first schema to compare
  @param entitySchema2
  The second schema to compare
  @return True if compatible, otherwise False.