DealMerger::canMergeEntityField

static function canMergeEntityField($fieldID)
{
	//Field ContactID is obsolete. It is replaced by ContactIDs
	//Field StageID is progress field
	if($fieldID === 'CONTACT_ID' || $fieldID === 'STAGE_ID')
	{
		return false;
	}
	return parent::canMergeEntityField($fieldID);
}