Calls loading Leads Logic Hook

<?php

// $hook_array['before_save'][] = Array(1, 'Call Log Handler', 'custom/modules/Calls/PSI_CallHandler.php','CallHandler', 'HandleCall');

class CallHandler{
    function HandleCall($bean, $event, $arguments){
        if(!($this->IsForaLead($bean) && $this->SubjectIsRelevant($bean))){
            return false;
        }
    $new_lead_status = null;
    // ...
        if(!is_null($new_lead_status))
            $this->changeLeadStatus($bean->parent_id,$new_lead_status);
    }

    function IsForaLead($callbean){
        if($callbean->parent_type == 'Leads' && $callbean->parent_id != ''){
            $leadbean = new Lead();
            $leadbean->retrieve($callbean->parent_id);
            if(!empty($leadbean->id) && !is_null($leadbean->id)){
                return true;
            } else {
                return false;
            }
        } else {
            return false;
        }
    }

    function SubjectIsRelevant($callbean){
    return true;
    }

    function changeLeadStatus($lead_id,$new_lead_status){
        $lead = new Lead();
        $lead->retrieve($lead_id);
        if($lead->status != $new_lead_status){
            $lead->status = $new_lead_status;
            $lead->save();
        }
    }
}