`MergingDocument` should override the equals method

Is your feature request related to a problem? Please describe.
MergingDocument should override the equals method

Describe the solution you'd like
add following code to MergingDocument

        @Override
        public boolean equals(Object o) {
            if (this == o) {
                return true;
            } else if (o instanceof Document document) {
                return this.entrySet().equals(document.entrySet());
            } else {
                return false;
            }
        }

Describe alternatives you've considered

Additional context

Locate the MergingDocument class and inspect how Document equality is currently handled. Add the requested equals override, then check the existing test structure for document comparisons and verify that MergingDocument and equivalent Document instances compare as expected.