Incorrect reflection call leads to compilation errors

[EgorkaKulikov]

Description

Try to generate tests for the following class, set timeout at least to 60s.

import org.antlr.runtime.tree.TreeVisitor;
import org.antlr.runtime.tree.TreeVisitorAction;
import org.antlr.v4.parse.GrammarASTAdaptor;
import org.antlr.v4.tool.ast.GrammarAST;

public class Grammarin {
 public void setGrammarPtr(final org.antlr.v4.tool.Grammar g, GrammarAST tree) {
 if (tree != null) {
 TreeVisitor v = new TreeVisitor(new GrammarASTAdaptor());
 v.visit(tree, new TreeVisitorAction() {
 public Object pre(Object t) {
 ((GrammarAST) t).g = g;
 return t;
 }

 public Object post(Object t) {
 return t;
 }
 });
 }
 }
}

The following code i generated:

 @Test
 @DisplayName("setGrammarPtr: -> tree != null : True")
 public void testSetGrammarPtr_TreeNotEqualsNull_2() throws ClassNotFoundException, NoSuchFieldException, IllegalAccessException {
 Grammarin grammarin = new Grammarin();
 GrammarRootAST tree = new GrammarRootAST(null);
 tree.token = null;
 Class baseTreeClazz = Class.forName("org.antlr.runtime.tree.BaseTree");
 Field childrenField = baseTreeClazz.getDeclaredField("children");
 childrenField.setAccessible(true);
 childrenField.get(tree) = new ArrayList();

 grammarin.setGrammarPtr(null, tree);
 }

Line with getter leads to the compilation error

childrenField.get(tree) = new ArrayList(); - variable expected

[volivan239]

Fixed by #1029