ADDITIONAL SYSTEM INFORMATION :
Java: 19; OpenJDK 64-Bit Server VM 19+36-2238
Runtime: OpenJDK Runtime Environment 19+36-2238
System: Windows 11 version 10.0 running on amd64; UTF-8; en_US (nb)

A DESCRIPTION OF THE PROBLEM :
if we have a class like this
public class SomeClass {
String string_property;
@Override
    public boolean equals(Object o) {
        if (o instanceof String) {
//First If Statement
            String external_string_value = (String)o;
            return string_property.equalsIgnoreCase(external_string_value);
        }
if (o instanceof SomeClass) {
//Second If Statement
return string_property.equalsIgnoreCase(((SomeClass)o).string_property);
}
return false;
}
}

and ArrayList like this

ArrayList<SomeClass> some_class_list = new ArrayList<>();
//Add some runtime objects
//some_class_list.add()

When I try to search inside ArrayList using methods like contains()
some_class_list.contains("select some object where search string equals SomeClass.string_property");//returns false since First if Statement will never ever be called
some_class_list.contains(some_class_object);//return true ssince Second If Statement

Why contains method returns false, it becuase of these lines of code inside indexOfRange and lastIndexOfRange
if (o.equals(es[i])) {
return i;
}

this lines of code needs a small modification to allow Java primitive objects to be used in conjunction between Object.equals() and ArrayList.contains()
if (es[i] != null && es[i].equals(o)) {
return i;
}

now Java ArrayList has the freedom to pass any object kind to perform matching against.