code: public void setColumnMapping(Map<String, String> columnMapping) {
        this.columnMapping.clear();
        for (Map.Entry<String, String> entry : columnMapping.entrySet()) {
           this.columnMapping.put(entry.getKey().toUpperCase(), entry.getValue());
        }
     }
docs: Sets the column mapping to those passed in.
  @param columnMapping - source column mapping.