Method add_node_

mlx/data/core/Graph.cpp:14–18

namespace core {
GraphBase::GraphBase() {}
int64_t GraphBase::add_node_() {
  int64_t id = nodes_.size();
  nodes_.resize(id + 1);
  return id;
}
int64_t GraphBase::add_edge_(int64_t inode, int64_t onode) {
  if (inode < 0 || inode >= nodes_.size()) {
    throw std::runtime_error("Graph: invalid input node");