func (g *GraphDefinitionMarker) GetValueOk() (string, bool) {
	if g == nil || g.Value == nil {
		return "", false
	}
	return *g.Value, true
}
func (g *GraphDefinitionMarker) GetValueOk() (string, bool) {
	if g == nil || g.Value == nil {
		return "", false
	}
	return *g.Value, true
}
// GetValueOk returns a tuple with the Value field if it's non-nil, zero value otherwise
// and a boolean to check if the value has been set.