src/MapOfNumerics.php
public function increment($key, $delta = 1)
    {
        if ($this->has($key)) {
            $this->set(
                $key, 
                $this->get($key) + $delta
            );
        } else {
            $this->set($key, $delta);
        }

        return $this;
    }
public function increment($key, $delta = 1)
    {
        if ($this->has($key)) {
            $this->set(
                $key, 
                $this->get($key) + $delta
            );
        } else {
            $this->set($key, $delta);
        }

        return $this;
    }
public function increment ( $ key , $ delta = 1 ) { if ( $ this -> has ( $ key ) ) { $ this -> set ( $ key , $ this -> get ( $ key ) + $ delta ) ; } else { $ this -> set ( $ key , $ delta ) ; } return $ this ; }
Increment the value stored at the given key by the given delta.

@return $this
@since 1.0.3
@api
Increment the value stored at the given key by the given delta .