code: public boolean contains(String column) {
  		for ( String columnName : columnNames ) {
  			if ( columnName.equals( column ) ) {
  				return true;
  			}
  		}
  		return false;
  	}
docs: Check if a column is part of the row key columns.
  
  @param column the name of the column to check
  @return true if the column is one of the row key columns, false otherwise