src/Type/Definition/IDType.php
public function parseValue($value)
    {
        if (is_string($value) || is_int($value)) {
            return (string) $value;
        }

        throw new Error('Cannot represent value as ID: ' . Utils::printSafe($value));
    }
public function parseValue($value)
    {
        if (is_string($value) || is_int($value)) {
            return (string) $value;
        }

        throw new Error('Cannot represent value as ID: ' . Utils::printSafe($value));
    }
@param mixed $value

@return string

@throws Error