public SkillPresentable(Skill skill)
 {
     _base = skill;
 }
        private void FixupSkill(Skill previousValue)
        {
            if (previousValue != null && previousValue.ProjectSkills.Contains(this))
            {
                previousValue.ProjectSkills.Remove(this);
            }

            if (Skill != null)
            {
                if (!Skill.ProjectSkills.Contains(this))
                {
                    Skill.ProjectSkills.Add(this);
                }
                if (SkillId != Skill.SkillId)
                {
                    SkillId = Skill.SkillId;
                }
            }
        }