Only include classes if they contain a BodyDeclaration

import com.github.javaparser.ast.CompilationUnit;

import com.github.javaparser.ast.Node;

import com.github.javaparser.ast.NodeList;

import com.github.javaparser.ast.body.ClassOrInterfaceDeclaration;

import com.github.javaparser.ast.body.ConstructorDeclaration;

import com.github.javaparser.ast.body.FieldDeclaration;

import com.github.javaparser.ast.body.MethodDeclaration;

import com.github.javaparser.ast.body.*;

import com.github.javaparser.ast.expr.BooleanLiteralExpr;

import com.github.javaparser.ast.nodeTypes.NodeWithBody;

import com.github.javaparser.ast.stmt.*;

    public Visitable visit(ClassOrInterfaceDeclaration n, NodeHashSet<Node> arg) {

        boolean keep = arg.contains(n);

        Visitable v = super.visit(n, arg);

        return keep || !((Node) v).getChildNodes().isEmpty() ? v : null;

        boolean containsDeclarations = ((Node) v).getChildNodes().stream().anyMatch(BodyDeclaration.class::isInstance);

        return keep || containsDeclarations ? v : null;

    }

    // ========== Class body visitors ==========