code: private List<Statement> getInitLocation(MethodDeclaration node) {
      List<Statement> stmts = node.getBody().getStatements();
      if (!stmts.isEmpty() && stmts.get(0) instanceof SuperConstructorInvocation) {
        return stmts.subList(0, 1);
      }
      // java.lang.Object supertype is null. All other types should have a super() call.
      assert TypeUtil.isNone(
          ElementUtil.getDeclaringClass(node.getExecutableElement()).getSuperclass())
          : "Constructor didn't have a super() call.";
      return stmts.subList(0, 0);
    }
docs: Finds the location in a constructor where init statements should be added.