message: Fix the copy_from of hybrid
diff: @@ -489,6 +489,17 @@ public:
  return strategy_;
  }
  + Hybrid &operator=(const Hybrid &other)
  + {
  + if (&other == this) {
  + return *this;
  + }
  + EnableLinOp<Hybrid<ValueType, IndexType>>::operator=(other);
  + this->coo_->copy_from(other.get_coo());
  + this->ell_->copy_from(other.get_ell());
  + return *this;
  + }
  +
  protected:
  /**
  * Creates an uninitialized Hybrid matrix of specified method.
  