src/Collection.php
protected function checkType($item)
    {
        $type = $this->getItemType($item);
        if (! $this->type) {
            $this->type = $type;

            return true;
        }

        if ($this->type != $type) {
            return false;
        }

        return true;
    }
protected function checkType($item)
    {
        $type = $this->getItemType($item);
        if (! $this->type) {
            $this->type = $type;

            return true;
        }

        if ($this->type != $type) {
            return false;
        }

        return true;
    }
protected function checkType ( $ item ) { $ type = $ this -> getItemType ( $ item ) ; if ( ! $ this -> type ) { $ this -> type = $ type ; return true ; } if ( $ this -> type != $ type ) { return false ; } return true ; }
Checks the immutability of the elements type

@return boolean
Checks the immutability of the elements type