bundles/org.eclipse.packagedrone.repo/src/org/eclipse/packagedrone/repo/MetaKeys.java
public static String getString ( final Map<MetaKey, String> metadata, final String ns, final String key )
    {
        return getString ( metadata, ns, key, null );
    }
public static String getString ( final Map<MetaKey, String> metadata, final String ns, final String key )
    {
        return getString ( metadata, ns, key, null );
    }
Get a string from meta data
<p>
If the provided metadata set is <code>null</code>, then the result will
also be <code>null</code>.
</p>

@param metadata
the meta data map, may be <code>null</code>
@param ns
the namespace
@param key
the key
@return the value, as string, may be <code>null</code>