Objective : Add an additional WHERE clause to any given Clickhouse statement. I’m using the following Antlr grammars to generate Java classes for a lexer & parser. Lexer grammar https://github.com/ClickHouse/ClickHouse/blob/master/utils/antlr/ClickHouseLexer.g4 Parser grammar https://github.com/ClickHouse/ClickHouse/blob/master/utils/antlr/ClickHouseParser.g4 Problem : I cannot figure out/understand how to interact or create the appropriate POJOs for use with the generated classes that Antlr produces. Example of statement Goal