Remove FunctionInformation and replace it with FunctionDefinition.

src/test/java/Helper.java

@@ -16,8 +16,8 @@ public class Helper {
         return parser.parse();
     }
 
-    public static Map<String, FunctionInformation> getFuncs(ParseTree tree) {
-        var functionDefinitions = new HashMap<String, FunctionInformation>();
+    public static Map<String, FunctionDefinition> getFuncs(ParseTree tree) {
+        var functionDefinitions = new HashMap<String, FunctionDefinition>();
         new GetDefinitions(functionDefinitions, new HashMap<>(), new HashMap<>()).visit(tree);
         return functionDefinitions;
     }