public function getValue(MetadatableInterface $object, $namespace, $key)
    {
        $metadata = $this->get($object, $namespace, $key);
        if (null !== $metadata) {
            return $metadata->getValue();
        }

        return null;
    }
public function getValue(MetadatableInterface $object, $namespace, $key)
    {
        $metadata = $this->get($object, $namespace, $key);
        if (null !== $metadata) {
            return $metadata->getValue();
        }

        return null;
    }
public function getValue ( MetadatableInterface $ object , $ namespace , $ key ) { $ metadata = $ this -> get ( $ object , $ namespace , $ key ) ; if ( null !== $ metadata ) { return $ metadata -> getValue ( ) ; } return null ; }
Get metadata value related to an object, a namespace and a key.

@param MetadatableInterface $object
@param string               $namespace
@param string               $key

@return string | null
Get metadata value related to an object a namespace and a key .