code: public boolean createFunctions(String tableName, String columnName) {
  
  		boolean created = has(tableName, columnName);
  		if (created) {
  			createAllFunctions();
  		}
  		return created;
  	}
docs: Check if the table and column has the RTree extension and create the
  functions if needed
  
  @param tableName
  table name
  @param columnName
  column name
  @return true if has extension and functions created