unity/app/Models/ContractTemplate.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class ContractTemplate extends Model
{
    protected $table = 'contract_templates';

     protected $appends = ['contract_template_obligation_list'];

    public function contract_template_obligation()
    {
        return $this->hasMany('App\Models\ContractTemplateObligation', 'contract_template_id');
    }

    public function getContractTemplateObligationListAttribute()
    {
        return $this->contract_template_obligation()->get();
    }
}