src/LightSaml/Model/Metadata/KeyDescriptor.php
public function setUse($use)
    {
        $use = trim($use);
        if (false != $use && self::USE_ENCRYPTION != $use && self::USE_SIGNING != $use) {
            throw new \InvalidArgumentException(sprintf("Invalid use value '%s'", $use));
        }
        $this->use = $use;

        return $this;
    }
public function setUse($use)
    {
        $use = trim($use);
        if (false != $use && self::USE_ENCRYPTION != $use && self::USE_SIGNING != $use) {
            throw new \InvalidArgumentException(sprintf("Invalid use value '%s'", $use));
        }
        $this->use = $use;

        return $this;
    }
@param string $use

@return KeyDescriptor

@throws \InvalidArgumentException