code: protected String[] getProjection() {
  		String[] projection = new String[getColumns().length];
  		for (int i = 0; i < projection.length; i++) {
  			projection[i] = getColumns()[i].getColumnName();
  		}
  		return projection;
  	}
docs: Returns the default projection which includes all the columns defined by {@link #getColumns()}
  
  @return the projection.