Adding an Antlr4 parse tree to another Antlr4 parse tree -

i need implement generics antlr4. in order this, need able take class and, used, dynamically generate code macro, tokenize code, generate tree, , add new tree original parse tree.

i saw these 2 classes

http://www.antlr.org/api/javatool/org/antlr/v4/runtime/rulecontext.html

http://www.antlr.org/api/javatool/org/antlr/v4/runtime/parserrulecontext.html

however, i'm not sure do, nor sure how use constructor.

parserrulecontext(parserrulecontext parent, int invokingstatenumber)

rulecontext(rulecontext parent, int invokingstate)

specifically, these classes represent new tree, , should pass invokingstate/invokingstatenumber?

apparently easy this

when walking first tree, correctly displays information both files.

    public class program     {             private static parserrulecontext gettree(string file) throws exception             {                     inputstream input = new fileinputstream(file);                     reader reader = new inputstreamreader(input);                     antlrinputstream inputstream = new antlrinputstream(reader);                      javalexer lexer = new javalexer(inputstream);                     commontokenstream tokens = new commontokenstream(lexer);                     javaparser parser = new javaparser(tokens);                     parserrulecontext tree = parser.compilationunit(); // parse                      return tree;             }              public static void main(string args[]) throws exception             {                     parserrulecontext tree1 = gettree("e:\\users\\nessy\\ideaprojects\\antlrtest\\src\\in1.java");                     parserrulecontext tree2 = gettree("e:\\users\\nessy\\ideaprojects\\antlrtest\\src\\in2.java");                      tree1.addchild(tree2);                      parsetreewalker walker = new parsetreewalker(); // create standard walker                     javawalker extractor = new javawalker();                     walker.walk(extractor, tree1); // initiate walk of tree listener             }     }