code: func (m *Mrb) SetGlobalVariable(name string, value Value) {
  	cs := C.CString(name)
  	defer C.free(unsafe.Pointer(cs))
  
  	v := value.MrbValue(m)
  	C._go_mrb_gv_set(m.state, C.mrb_intern_cstr(m.state, cs), v.value)
  }
docs: // SetGlobalVariable sets the value of the global variable by the given name.