// Pseudo code

/**
 * Returns if the pickup delay is over.
 * 
 * @return If the pickup delay is over.
 */
private boolean isPickupDelayOver() {
    return this.pickupDelay == 0;
}

/**
 * Returns if the item entity can be picked up by the given entity. For non-entities call {@code #canBePickedUp()}.
 * 
 * @param entity The entity which should be tested
 * @return If the given entity can pick up this item entity 
 */
public boolean canBePickedUp(Entity entity) {
    if (this.isPickupDelayOver()) {
        if (this.owner == null || this.owner.equals(entity)) {
            return true;
        }
    }
    
    return false;
}

/**
 * Returns if the item entity can be picked up by a non-entity. For entities call {@code #canBePickedUp(Entity)}.
 * 
 * @return If the item entity can be picked up by a non-entity
 */
public boolean canBePickedUp() {
    return this.isPickupDelayOver() && this.owner == null;
}