{@inheritdoc}

@return bool|null
971324
public function isNullable()
    {
        if (null === $this->nullable) {
            return null;
        }

        return $this->nullable || 'null' === strtolower($this->getDefault() ?? '');
    }
386497
public function offsetGet($offset) : ?Collection {
        return $this->has($offset) ? $this->collection($offset) : null;
    }
1194862
public function get($key)
    {
        if( isset($this->values[$key]) ) {
            return $this->values[$key];
        } else {
            return null;
        }
    }
788406
public function request($value)
    {
        if (!isset($this->request[$value])) {
            return false;
        } else {
            return $this->request[$value];
        }
    }
467778
public function get($value)
    {
        return isset($this->items[$value]) ? $this->items[$value] : null;
    }
292601
public function __isset($property)
    {
        if (method_exists($this, $getter = 'get' . $property)) {
            return $this->$getter() !== null;
        } else {
            return false;
        }
    }
56812
public function getValue($key = null)
    {
        if (is_null($key)) {//返回所有
            return $this->args;
        } elseif (isset($this->args[$key])) {
            return $this->args[$key];
        } else {
            return null;
        }
    }
144921
public function offsetGet($offset)
    {
        return isset($this->object[$offset]) ? $this->object[$offset] : null;
    }
260411
public function last($return = false)
    {
        if (!empty($this->query)) {
            if ($return) {
                return $this->query;
            }
            var_dump($this->query);
            return null;
        }
        return false;
    }
708754
public function get($object = false)
    {
        $this->prepare();

        return $this->prepareResult($this->_map, $object);
    }
1047444
public function get($name)
    {
        return isset($this->value[$name])
            ? $this->value[$name]
            : null;
    }
1287623
protected function get($field)
    {
        if (isset($this->raw[$field])) {
            return $this->raw[$field];
        }
        if (preg_match('/^is_/', $field)) {
            return false;
        }

        return null;
    }
313735
public function find($username)
    {
        $response = $this->search($username);
        foreach ($response->get() as $user) {
            if ($username === $user['username']) {
                return $this->get($user['id']);
            }
        }
        return null;
    }
598351
final public function get($method = null) {

        if ( empty($method) ) {

            $return = $this->rpc_methods;

        } else if ( array_key_exists($method, $this->rpc_methods) ) {

            $return = $this->rpc_methods[$method];

        } else {

            $return = null;

        }

        return $return;

    }
765055
public function query($name)
    {
        $exists = isset($this->queries[$name]);

        return $exists ? $this->queries[$name] : null;
    }
1142911
public function get($id) {
		if (! $this->connectionCheckStatus) {
			$this->addServer();
		}
		
		$result = $this->getClient()->get($this->prepareId($id));
		
		return $result === false ? null : $result;
	}
1246525
public function next() {
		$value = next($this->_data);
		return key($this->_data) !== null ? $value : false;
	}