Is there a way to get back source code from antlr4ts parse tree after modifications ctx.removeLastChild/ctx.addChild?

Question

I am working on custom language syntax and need to get back modified source code. The "text" property (https://github.com/tunnelvisionlabs/antlr4ts/blob/master/src/RuleContext.ts#L132) returns combined text representation of nodes but with missing spaces, so code is not valid.