code: func (m *Mrb) Close() {
  	// Delete all the methods from the state
  	stateMethodTable.Mutex.Lock()
  	delete(stateMethodTable.Map, m.state)
  	stateMethodTable.Mutex.Unlock()
  
  	// Close the state
  	C.mrb_close(m.state)
  }
docs: // Close a Mrb, this must be called to properly free resources, and
  // should only be called once.