public BaseSpecification <TEntity> Or(BaseSpecification <TEntity> spec)
 {
     return(new OrSpecification <TEntity>(this, spec));
 }
 public OrSpecification(BaseSpecification <TEntity> left, BaseSpecification <TEntity> right)
 {
     _right = right;
     _left  = left;
 }
 public BaseSpecification <TEntity> And(BaseSpecification <TEntity> spec)
 {
     return(new AndSpecification <TEntity>(this, spec));
 }