encoding.php
public function add($key, $value)
    {
        if ($value === false) {
            return;
        }
        if (is_array($value)) {
            foreach ($value as $item) {
                $this->addPair($key, $item);
            }
        } else {
            $this->addPair($key, $value);
        }
    }
public function add($key, $value)
    {
        if ($value === false) {
            return;
        }
        if (is_array($value)) {
            foreach ($value as $item) {
                $this->addPair($key, $item);
            }
        } else {
            $this->addPair($key, $value);
        }
    }
Adds a parameter to the query.

@param string $key            Key to add value to.
@param string/array $value    New data.