private StepModelHelper Insert(MetadataAttributeModel childModel, StepModelHelper stepModelHelperParent, int number)
{
MetadataAttributeModel childrensWithSameUsage = stepModelHelperParent.Model.MetadataAttributeModels.Where(m => m.Source.Id.Equals(childModel.Source.Id)).First();
int indexOfFirstUsage = stepModelHelperParent.Model.MetadataAttributeModels.IndexOf(childrensWithSameUsage);
stepModelHelperParent.Model.MetadataAttributeModels.Insert(indexOfFirstUsage + number - 1, childModel);
return stepModelHelperParent;
}