class SingleIndexProperties implements IndexProperties {

    private final Object property;

    SingleIndexProperties(Object property) {
        this.property = property;
    }

    @Override
    public <Type_> Type_ toKey(int index) {
        if (index != 0) {
            throw new IllegalArgumentException("Impossible state: index (" + index + ") != 0");
        }
        return (Type_) property;
    }

    @Override
    public <Type_> Type_ toKey(int from, int to) {
        if (to != 1) {
            throw new IllegalArgumentException("Impossible state: key from (" + from + ") to (" + to + ").");
        }
        return toKey(from);
    }

    @Override
    public boolean equals(Object o) {<FILL_FUNCTION_BODY>}

    @Override
    public int hashCode() { // Not using Objects.hash(Object...) as that would create an array on the hot path.
        return Objects.hashCode(property);
    }

    @Override
    public String toString() {
        return "[" + property + "]";
    }

}

        if (this == o) {
            return true;
        }
        if (!(o instanceof SingleIndexProperties)) {
            return false;
        }
        SingleIndexProperties other = (SingleIndexProperties) o;
        return Objects.equals(property, other.property);
    
<no_super_class>