Error in save() after an function in Laravel - php

Question

I am trying to implement the save() method after the self::restrictionMinimunBid($ request, $ karateka, $ bid) function, but I get the following error: "Method App\\Http\\Controllers\\BidController::save does not exist."
Here is my code:
$bid = Bid::where('id_participants', '=', $request->id_participant)
->where('id_karatekas', '=',$market->id_karatekas)
->where('bid', '=',$request->bid);
if(!$bid->count()){
$bid->id_market = $market->id;
$bid->id_group = $market->id_group;
$bid->id_karatekas = $market->id_karatekas;
$bid->id_participants = $request->id_participant;
self::restrictionMinimunBid($request, $karateka, $bid);
$bid->save();
$response = array('code' => 200, 'Bid' => $bid, 'msg' => 'Bid created');
}else{
$response = array('code' => 400, 'error_msg' => "Bid already registered.");
}
public function restrictionMinimunBid(Request & $request, $karateka, & $bid)
{
$allKaratekas = Karateka::all()
->map(function ($allKaratekas) use ($karateka, $request, $bid){
if($karateka->id == $allKaratekas->id ){
if($request->bid > $allKaratekas->value){
$bid->bid = $request->bid;
$msg ="The bid is more than the value of karateka";
var_dump($msg);
}
else{
$error ="The bid is less than the value ofmkarateka";
var_dump($error);
}
}
});
}

Answer 1

You can replace this one:
$bid = Bid::where('id_participants', '=', $request->id_participant)
->where('id_karatekas', '=',$market->id_karatekas)
->where('bid', '=',$request->bid);
To this:
$bid = Bid::where('id_participants', '=', $request->id_participant)
->where('id_karatekas', '=',$market->id_karatekas)
->where('bid', '=',$request->bid)->first();