src/Storage/Configurator/AbstractConfigurator.php
public function assertIntOrFalse($config, $key, $lowest = null, $highest = null)
    {
        try {
            $this->assertInteger($config, $key, $lowest, $highest);
        } catch (ConfigurationException $e) {
            if ($config[$key]!==false) {
                throw new ConfigurationException(
                    "Key `{$key}` can be either false or a non-negative integer."
                );
            }
        }
        return $this;
    }
public function assertIntOrFalse($config, $key, $lowest = null, $highest = null)
    {
        try {
            $this->assertInteger($config, $key, $lowest, $highest);
        } catch (ConfigurationException $e) {
            if ($config[$key]!==false) {
                throw new ConfigurationException(
                    "Key `{$key}` can be either false or a non-negative integer."
                );
            }
        }
        return $this;
    }
Assert the value is either integer within bounds or false

Some configuration values can be either false (disabled)
or have an integer value set if enabled

@param array $config
@param string|int $key Array being validated
@param int $lowest The lowest accepted value
@param int $highest The highest accepted value
@return $this
@throws ConfigurationException On a failed assertation