message: Remove redundant check
  already done in the caller
diff: @@ -62,7 +62,6 @@ class Simplex_tree_interface : public Simplex_tree<SimplexTreeOptions> {
  void insert_matrix(double* filtrations, int n, int stride0, int stride1, double max_filtration) {
  // We could delegate to insert_graph, but wrapping the matrix in a graph interface is too much work,
  // and this is a bit more efficient.
  - assert(this->num_simplices() == 0);
  auto& rm = this->root()->members_;
  for(int i=0; i<n; ++i) {
  char* p = (char*)filtrations + i * stride0;
  