code: @Override
  	public void setFileExtension(final String fileExtension) {
  		if (fileExtension == null) {
  			LOG.warn("Use the default value because SQL template extension is set to NULL.");
  			LOG.warn("Default SQL template extension[{}]", DEFAULT_FILE_EXTENSION);
  			this.fileExtension = DEFAULT_FILE_EXTENSION;
  		} else {
  			this.fileExtension = fileExtension;
  		}
  	}
docs: {@inheritDoc}
  
  @see jp.co.future.uroborosql.store.SqlLoader#setFileExtension(java.lang.String)