selectRow and paginate laravel

var $model_class = 'App\Modules\Calls\Models\Calls';
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$data 	= $this->model_class::select(DB::raw($this->table_module.".*,
									sys_rel.rel_to_module as module_name,
									sys_rel.rel_to_id as module_id,
									(CASE rel_to_module
							     			WHEN sys_rel.rel_to_module = 'leads' THEN ( SELECT CONCAT(leads.leads_first_name, ' ', leads.leads_last_name) FROM leads WHERE leads.leads_serial_id = module_id LIMIT 1)
							         	WHEN sys_rel.rel_to_module = 'contacts' THEN ( SELECT CONCAT(contacts.contacts_first_name, ' ', contacts.contacts_last_name) FROM contacts WHERE contacts.contacts_serial_id = module_id LIMIT 1)
							         	WHEN sys_rel.rel_to_module = 'org'  THEN ( SELECT org_name FROM org WHERE org.org_serial_id = module_id LIMIT 1)
							         	WHEN sys_rel.rel_to_module is NULL THEN '-'
							    END) as ".$this->table_module."_parent_id"))
								->leftjoin('sys_rel', 'sys_rel.rel_serial_id', '=', $this->table_module.'.rel_serial_id')
								->where($this->table_module.'.rel_serial_id', '>', 0)
								->where('company_id', '=', $company_id)
								->where('deleted', '=', '0')
								->orderBy($order_by, $type_sort)
								->paginate($this->pagesize);