public void insertBefore(String programName, int index, Object text) {
		RewriteOperation op = new InsertBeforeOp(index,text);
		List<RewriteOperation> rewrites = getProgram(programName);
		op.instructionIndex = rewrites.size();
		rewrites.add(op);
	}
Reset the program so that no instructions exist
runtime/Java/src/org/antlr/v4/runtime/TokenStreamRewriter.java